Add various alternate file extensions to lexers

These should be pretty clear cases.

Author: silverwind

Diff for: lexers/h/handlebars.go

@@ -9,8 +9,8 @@ import (
 var Handlebars = internal.Register(MustNewLexer(
 	&Config{
 		Name:      "Handlebars",
-		Aliases:   []string{"handlebars"},
-		Filenames: []string{"*.handlebars"},
+		Aliases:   []string{"handlebars", "hbs"},
+		Filenames: []string{"*.handlebars", "*.hbs"},
 		MimeTypes: []string{},
 	},
 	Rules{

Diff for: lexers/j/javascript.go

@@ -65,7 +65,7 @@ var Javascript = internal.Register(MustNewLexer(
 	&Config{
 		Name:      "JavaScript",
 		Aliases:   []string{"js", "javascript"},
-		Filenames: []string{"*.js", "*.jsm"},
+		Filenames: []string{"*.js", "*.jsm", "*.mjs"},
 		MimeTypes: []string{"application/javascript", "application/x-javascript", "text/x-javascript", "text/javascript"},
 		DotAll:    true,
 		EnsureNL:  true,

Diff for: lexers/p/powershell.go

@@ -9,8 +9,8 @@ import (
 var Powershell = internal.Register(MustNewLexer(
 	&Config{
 		Name:            "PowerShell",
-		Aliases:         []string{"powershell", "posh", "ps1", "psm1"},
-		Filenames:       []string{"*.ps1", "*.psm1"},
+		Aliases:         []string{"powershell", "posh", "ps1", "psm1", "psd1"},
+		Filenames:       []string{"*.ps1", "*.psm1", "*.psd1"},
 		MimeTypes:       []string{"text/x-powershell"},
 		DotAll:          true,
 		CaseInsensitive: true,