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/Makefile

@@ -0,0 +1,26 @@
+generate:
+	go generate
+	go generate ./...
+.PHONY: generate
+
+download_schema:
+	go run ./cmd/dltl -base https://raw.githubusercontent.com/tdlib/td -branch master -dir td/generate/scheme -f telegram_api.tl -o _schema/tdlib.tl
+	go run ./cmd/dltl -base https://raw.githubusercontent.com/telegramdesktop/tdesktop -branch dev -dir Telegram/SourceFiles/mtproto/scheme -f api.tl -o _schema/tdesktop.tl
+	go run ./cmd/dltl -base https://raw.githubusercontent.com/telegramdesktop/tdesktop -branch dev -dir Telegram/SourceFiles/mtproto/scheme -f api.tl -merge _schema/legacy.tl -o _schema/telegram.tl
+.PHONY: download_schema
+
+download_public_keys:
+	go run ./cmd/dlkey -o internal/mtproto/_data/public_keys.pem
+.PHONY: download_public_keys
+
+download_e2e_schema:
+	go run ./cmd/dltl -f secret_api.tl -o _schema/encrypted.tl
+.PHONY: download_e2e_schema
+
+download_tdlib_schema:
+	go run ./cmd/dltl -f td_api.tl -o _schema/tdapi.tl
+.PHONY: download_tdlib_schema
+
+check_generated: generate
+	git diff --exit-code
+.PHONY: check_generated