fix: RTL support on post textarea

Fixing right to left (short: RTL) support for respective RTL languages
by adding auto-detection for the user content's directionality based on
the text's language.

Fixes #612

templates/bare.tmpl

@@ -14,7 +14,7 @@
 
 		<div id="overlay"></div>
 		
-		<textarea id="writer" placeholder="Write..." class="{{.Post.Font}}" autofocus>{{if .Post.Title}}# {{.Post.Title}}
+		<textarea dir="auto" id="writer" placeholder="Write..." class="{{.Post.Font}}" autofocus>{{if .Post.Title}}# {{.Post.Title}}
 
 {{end}}{{.Post.Content}}</textarea>
 

templates/pad.tmpl

@@ -14,7 +14,7 @@
 
 		<div id="overlay"></div>
 		
-		<textarea id="writer" placeholder="Write..." class="{{.Post.Font}}" autofocus>{{if .Post.Title}}# {{.Post.Title}}
+		<textarea dir="auto" id="writer" placeholder="Write..." class="{{.Post.Font}}" autofocus>{{if .Post.Title}}# {{.Post.Title}}
 
 {{end}}{{.Post.Content}}</textarea>