Update changelog

client/doc/developing/changelog.rst

@@ -1,8 +1,61 @@
 Changelog (Version History)
 ===========================
 
+v2.0-alpha.0
+------------
 
-v2 alpha
++------------------------+
---------
+| Scheme layer used: 165 |
++------------------------+
 
-WIP!
+`View new and changed raw API methods <https://diff.telethon.dev/?to=165>`__.
+
+.. important::
+
+    **The first alpha of Telethon v2 is here!**
+
+What a ride!
+
+This has been a long-time coming and I am so glad I don't need to work on the old and messy code-base anymore!
+
+This changelog will no longer have catchy names for the different versions.
+It's been a while since I was able to come up with meaningful names, anyway.
+
+Instead of breaking down what's new, changed, or removed from this version, there is a migration guide.
+Be warned, it's a lot!
+But in short, this is mostly a "reset" to cut down on the bloat of the library.
+The library should still result familiar.
+
+.. seealso::
+
+    :doc:`migration-guide`
+
+Your v1 code likely won't be compatible with v2.
+However, a lot of effort has gone into making v2 type-safe.
+This means you can use static type-checkers to be confident you're using the new methods correctly.
+
+A lot of work has been put into ensuring the documentation is the best it can be.
+If you find any errata or confusing sections, please `open a Documentation Issue <https://github.com/LonamiWebs/Telethon/issues/new/choose>`_.
+
+.. rubric:: What happens to Telethon v1 now?
+
+Version 1 will probably be maintained for a while longer.
+
+New layers will be released, and bugs that make it unusable fixed.
+As long as I have the time to do so.
+This will not be a priority.
+There is no specific end-of-life date, but it will not last forever.
+
+No new features will be added to v1, or smaller bugs fixed.
+This should not be news to anyone, as it has already been the case for a while now.
+
+You can keep using v1 for now.
+But a lot of work has been put into v2 and its migration guide.
+I hope you can take this opportunity to migrate and dust off some of your old code!
+
+v1.x and below
+--------------
+
+The old `v1 changelog <https://docs.telethon.dev/en/v1/misc/changelog.html>`_ is still available online.
+And in the history of the repository.
+It has been removed from the current documentation to keep it lighter.

client/doc/developing/migration-guide.rst

@@ -82,7 +82,7 @@ You can no longer ``import telethon.sync`` to have most calls wrapped in :meth:`
 Raw API is now private
 ----------------------
 
-v2 aims to comply with `Semantic Versioning <https://semver.org/>`.
+v2 aims to comply with `Semantic Versioning <https://semver.org/>`_.
 This is impossible because Telegram is a live service that can change things any time.
 But we can get pretty close.