Added languages.go generator

cli/slinguist-generate/assets/languages.go.tmpl

@@ -0,0 +1,11 @@
+package slinguist
+
+// CODE GENERATED AUTOMATICALLY WITH github.com/src-d/simple-linguist/cli/slinguist-generate
+// THIS FILE SHOULD NOT BE EDITED BY HAND
+// Extracted from github/linguist commit: {{ getCommit }}
+
+var languagesByExtension = map[string][]string{
+	{{range $extension, $languages := . -}}
+	"{{ $extension }}":	{ {{- $languages | formatStringSlice -}} },
+	{{end -}}
+}