Move code rendering to the backend & frontend improvements (#176)

Added Chroma & Goldmark

Added Mermaidjs

More languages supported

Add default values for gist links input

Added copy code from markdown blocks

internal/git/output_parser.go

@@ -12,6 +12,7 @@ import (
 
 type File struct {
 	Filename    string
+	Size        string
 	OldFilename string
 	Content     string
 	Truncated   bool