Add Yard, and begin some documentation

Use Yard to generate documentation. Included in the `.yardopts` file is
configuration to also publish the markdown files in the `wiki/`
directory.

wiki/
- addons.md: Information on writing new addons.
- database.md: Information on using the database and migrations

db/migrate/*: Rename in accordance with documentation

Rakefile: Add the Yard Rake tasks

.yardopts

@@ -0,0 +1,5 @@
+--protected
+--private
+-
+wiki/database.md
+wiki/addons.md

Gemfile

@@ -9,3 +9,5 @@ gem "activerecord", "~> 6.1"
 gem "rake", "~> 13.0"
 
 gem "sqlite3", "~> 1.4"
+
+gem "yard", "~> 0.9.26"

Rakefile

@@ -4,7 +4,7 @@ namespace :chronicle do
     require 'active_record'
     require_relative 'lib/chronicle'
 
-    db_config = YAML::load(File.open('config/database.yml'))
+    db_config = YAML::load(File.open('config/db.yml'))
     ActiveRecord::Base.establish_connection(db_config)
 
     bot_config = YAML::load(File.open('config/bot.yml'))
@@ -18,18 +18,20 @@ namespace :db do
   require 'active_record'
   require 'yaml'
 
-  Dir[File.join(__dir__, 'db', 'migrate', '*.rb')].each do |file|
+  klasses = []
+  Dir[File.join(__dir__, 'db', 'migrate', '*.rb')].sort.each do |file|
     require file
+    klasses << file.split('_')[1..-1].map(&:capitalize).join[0..-4]
   end
 
   task :connect do
-    connection_details = YAML::load(File.open('config/database.yml'))
+    connection_details = YAML::load(File.open('config/db.yml'))
     ActiveRecord::Base.establish_connection(connection_details)
   end
 
   desc "Create a new database"
   task :create do
-    connection_details = YAML::load(File.open('config/database.yml'))
+    connection_details = YAML::load(File.open('config/db.yml'))
 
     if connection_details["adapter"] == 'sqlite3'
       if File.exists?(connection_details["database"])
@@ -48,12 +50,24 @@ namespace :db do
   desc "Run the migrations"
   task :migrate => 'db:connect' do
     # ActiveRecord::MigrationContext.new('db/migrate/').migrate()
-    CreateCustomCommands.migrate(:up)
+    # CreateCustomCommands.migrate(:up)
+    klasses.each do |k|
+      k.constantize.public_send('migrate', :up)
+    end
   end
 
   desc "Clear the database"
   task :drop => 'db:connect' do
     # ActiveRecord::Migration.migrate(:down)
-    CreateCustomCommands.migrate(:down)
+    # CreateCustomCommands.migrate(:down)
+    klasses.each do |k|
+      k.constantize.public_send('migrate', :down)
+    end
   end
 end
+
+namespace :dev do
+  require 'yard'
+
+  YARD::Rake::YardocTask.new
+end

db/migrate/0001_create_general.rb

@@ -0,0 +1,15 @@
+class CreateGeneral < ActiveRecord::Migration[6.1]
+  def up
+    create_table :general do |table|
+      table.string :roomid
+      table.string :protocol
+      table.string :prefix_char
+      table.integer :permission_level
+      table.timestamps
+    end
+  end
+
+  def down
+    drop_table :general
+  end
+end

db/migrate/0100_create_custom_commands.rb

@@ -1,4 +1,4 @@
-class CreateCustomCommands < ActiveRecord::Migration[5.2]
+class CreateCustomCommands < ActiveRecord::Migration[6.1]
   def up
     create_table :custom_commands do |table|
       table.string :roomid

wiki/addons.md

@@ -0,0 +1,19 @@
+# @markup markdown
+# @title Add-Ons
+
+# Chronicle Add-ons
+
+Add-ons represent functionality that may not be universally enabled or desired
+by default. Provided examples include a dice roller, a custom command handler,
+and some simple games.
+
+Writing an add-on for Chronicle is relatively straight forward, and being
+refined as I develop it more.
+
+## Creating an Add-on
+
+### General requirements
+
+### Protocol requirements
+
+### Database requirements

wiki/database.md

@@ -0,0 +1,78 @@
+# @markup markdown
+# @title Database
+
+# Chronicle Database
+
+Chronicle leverages a database for persistent storage. It uses ActiveRecord for
+interfacing with the supported database types, performing migrations, and
+interacting with models.
+
+## Supported Databases
+
+### Currently Supported:
+
+- SQLite
+
+### Planned Support:
+
+- PostgreSQL
+- MySQL
+- MariaDB
+
+## Creating the Database
+
+There's a Rake task for creating the database according to ActiveRecord: `rake
+db:create`. For configuration, check out `config/db.yml`. The default
+configuration will create a SQLite3 database at `db/chronicle-bot.db`.
+
+## Working With the Migrations
+
+ActiveRecord migrations are database-agnostic schema alterations, stored as
+code. This allows Chronicle to support multiple different database
+architectures, without having to write custom code for each one.  Migrations can
+represent changes tied to new versions, or additional database configuration
+tied to an add-on or protocol, for example.
+
+To apply the migrations, use the Rake task `rake db:migrate`.
+
+To roll-back the migrations, use the Rake task `rake db:down`.
+
+### Provided Migrations
+
+By default, Chronicle includes a migration for setting up the "general" table,
+which provides details around the bot itself.
+
+It also includes a migration for the Custom Commands add-on, which creates a
+table for storing the commands and responses, along with the room ID the command
+was created in.
+
+Each of these migrations include a "roll-back" solution, which simply drops the
+corresponding tables.
+
+### Writing Additional Migrations
+
+The most important thing when creating new migrations is to follow the naming
+convention: 
+
+```
+   XXXX_name_of_migration.rb
+```
+
+The Rake tasks for working with migrations will look at every file in the
+`db/migrate/` directory, and sort them. It will `require` those files, and then
+compile a list of the classes within those files according to specific logic: it
+takes the file name, drops the numbers at the beginning, and converts the file
+name from snake case and to camel case, dropping the file extension. For example,
+"0000_create_general.rb" will be processed to the class named "CreateGeneral",
+which will be added to a list. The Rake task will then go through each the list
+of all classes and run the "migrate" method of each class, passing it "up" if
+migrations are being applied, or "down" if migrations are being rolled-back.
+
+Generally speaking, the number for the migration is mostly important for sorting
+order. However, a simple naming convention can help distinguish between types of
+migrations, by changing the 2nd-position digit:
+
+- For migrations tied to Chronicle functionality, use `00XX`.
+- For migrations tied to addon functionality, use `01XX`.
+- For migrations tied to protocol functionality, use `02XX`.
+- For any miscellaneous migrations, use `03XX`.