added fetchFromGitea to docs

doc/builders/fetchers.chapter.md

@@ -72,6 +72,10 @@ Used with Mercurial. Expects `url`, `rev`, and `sha256`.
 
 A number of fetcher functions wrap part of `fetchurl` and `fetchzip`. They are mainly convenience functions intended for commonly used destinations of source code in Nixpkgs. These wrapper fetchers are listed below.
 
+## `fetchFromGitea` {#fetchfromgitea}
+
+`fetchFromGitea` expects five arguments. `domain` is the gitea server name. `owner` is a string corresponding to the Gitea user or organization that controls this repository. `repo` corresponds to the name of the software repository. These are located at the top of every Gitea HTML page as `owner`/`repo`. `rev` corresponds to the Git commit hash or tag (e.g `v1.0`) that will be downloaded from Git. Finally, `sha256` corresponds to the hash of the extracted directory. Again, other hash algorithms are also available but `sha256` is currently preferred.
+
 ## `fetchFromGitHub` {#fetchfromgithub}
 
 `fetchFromGitHub` expects four arguments. `owner` is a string corresponding to the GitHub user or organization that controls this repository. `repo` corresponds to the name of the software repository. These are located at the top of every GitHub HTML page as `owner`/`repo`. `rev` corresponds to the Git commit hash or tag (e.g `v1.0`) that will be downloaded from Git. Finally, `sha256` corresponds to the hash of the extracted directory. Again, other hash algorithms are also available but `sha256` is currently preferred.