move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/telegram/message/styling/option.go

@@ -0,0 +1,43 @@
+package styling
+
+import (
+	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/message/entity"
+)
+
+// StyledTextOption is an option for styling text.
+type StyledTextOption struct {
+	size    int
+	perform func(b *textBuilder) error
+}
+
+// Zero returns true if option is zero value.
+func (s StyledTextOption) Zero() bool {
+	return s.perform == nil
+}
+
+func styledTextOption(s string, perform func(b *textBuilder) error) StyledTextOption {
+	return StyledTextOption{
+		perform: perform,
+		size:    len(s),
+	}
+}
+
+// Plain formats text without any entities.
+func Plain(s string) StyledTextOption {
+	return styledTextOption(s, func(b *textBuilder) error {
+		b.Plain(s)
+		return nil
+	})
+}
+
+// Custom formats text using given callback.
+func Custom(cb func(eb *entity.Builder) error) StyledTextOption {
+	return StyledTextOption{
+		size: 0,
+		perform: func(b *textBuilder) error {
+			return cb(b.Builder)
+		},
+	}
+}
+
+//go:generate go run go.mau.fi/mautrix-telegram/pkg/gotd/telegram/message/internal/mkentity -template styling -output options.gen.go