See yarn.
Run
gradlew yarn
and the enigma user interface will appear. Edit the mappings; when you are ready, save it in enigma, commit in git (preferably in a custom branch), and submit a pull request.
If you have changes done manually/from github suggestions, merge the remote branch, close enigma, and run the command again so that enigma can have the updated mapping contents.
See mappings.
Existing yarn builds approximately after 20w14a (1.16) have javadoc generated. They are accessible at
https://maven.fabricmc.net/docs/yarn-[minecraft version]+build.[build number]
For example, the javadoc for yarn 21w05b+build.8 is available at https://maven.fabricmc.net/docs/yarn-21w05b+build.8/
Run
gradlew javadoc
to generate javadoc from yarn's mappings. They will be built in the
build/docs/javadoc
directory relative to the repository root, and you can open index.html to view the docs.
Though enigma comes with procyon, you may want other decompilers to decompile the Minecraft jar with yarn names. Run
gradlew mapNamedJar
After running the gradle task, a <version>-named.jar will be available, which you can put into your desired decompiler.