Contributions possible due gitea configuration

What I today learnt on IRC
12:39 < stappers> How to "merge request"?  ( or how to get beyond the 404 from
    https://codeberg.org/meli/meli/compare/master...stappers/meli:debchangelog
    ? )
13:53 < manospitsid> stappers: I think merge requests in codeberg
    are turned off since it is only a mirror, you'd have to do it on
    the main repository (you can login with your codeberg account,
    no sign-up necessary)
14:00 < stappers> ( The owner has already reached the limit of 0 repositories.
    ( I will try harder. ) )
14:01 < manospitsid> oh
14:01 < manospitsid> did you try creating a new repo? try creating a fork of
    meli
14:01 < manospitsid> instead
14:03 < stappers> a fork of meli:  https://codeberg.org/stappers/meli/
14:04 < manospitsid> I mean creating a new fork on git.meli-email.org
14:05 < manospitsid> then you can add it as a remote in your local repository
    for example
14:05 < manospitsid> git remote add origin2 git://...
14:05 < stappers> There is now https://git.meli-email.org/stappers/meli
14:05  * stappers continues with the merge request

Signed-off-by: Geert Stappers <stappers@stappers.it>

README.md

@@ -20,6 +20,7 @@ Try an [old online interactive web demo](https://meli-email.org/wasm2.html "onli
 - [Non-exhaustive list of features](#non-exhaustive-list-of-features)
 - [HTML Rendering](#html-rendering)
 - [Documentation](#documentation)
+- [Contribute](#contribute)
 
 ## Install
 
@@ -151,3 +152,10 @@ or
 ```sh
 meli -c ./test_config
 ```
+
+## Contribute
+
+For code contributions like _merge requests_, is the gitea server
+configured to use various identity providers.
+No need for extra account creation.
+But you need to _"fork"_ at the gitea server.