Create and initialize Highlighter in TextEdit

ui/buffer/language.go

@@ -0,0 +1,23 @@
+package buffer
+
+import "regexp"
+
+type Syntax uint8
+
+const (
+	Default Syntax = iota
+	Keyword
+	Special
+	Type
+	Number
+	Builtin
+	Comment
+	DocComment
+)
+
+type Language struct {
+	Name      string
+	Filetypes []string // .go, .c, etc.
+	Rules     map[*regexp.Regexp]Syntax
+	// TODO: add other language details
+}