(new): rich messages, tgfmt DSL, Bot API 10.1

(fix): editMessageText rich_message type
(tests): rich and API 10.1 coverage
(doc): rich godoc, CHANGELOG v1.1.0

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tgfmt/utils.go

@@ -2,6 +2,15 @@ package tgfmt
 
 import "strings"
 
+func escapeHTML(s string) string {
+	s = strings.ReplaceAll(s, "&", "&")
+	s = strings.ReplaceAll(s, "<", "&lt;")
+	s = strings.ReplaceAll(s, ">", "&gt;")
+	s = strings.ReplaceAll(s, `"`, "&quot;")
+	return s
+}
+func escapeRich(s string) Rich { return Rich(escapeHTML(s)) }
+
 // EscapePunctuation escapes '.', '!' and '-' for MarkdownV2 fragments.
 func EscapePunctuation(s string) string {
 	symbols := []string{".", "!", "-"}