fix(version): change development version naming to avoid breaking some clients

Some Miniflux clients expect a specific version format.
For example, Flux News converts the string version to an integer.

Using `Development Version` will break some clients.

internal/template/functions.go

@@ -32,6 +32,7 @@ type funcMap struct {
 // Map returns a map of template functions that are compiled during template parsing.
 func (f *funcMap) Map() template.FuncMap {
 	return template.FuncMap{
+		"contains":         strings.Contains,
 		"startsWith":       strings.HasPrefix,
 		"formatFileSize":   formatFileSize,
 		"dict":             dict,

internal/template/templates/views/about.html

@@ -13,10 +13,10 @@
     <ul>
         <li>
             <strong>{{ t "page.about.version" }}</strong>
-            {{ if startsWith .version "2." }}
-                <a href="https://github.com/miniflux/v2/releases/tag/{{ .version }}">{{ .version }}</a>
-            {{ else }}
+            {{ if contains .version "dev" }}
                 {{ .version }}
+            {{ else }}
+                <a href="https://github.com/miniflux/v2/releases/tag/{{ .version }}">{{ .version }}</a>
             {{ end }}
         </li>
 	{{ if .commit }}