docs: describe how to get latest build

Author: spumer

README.md

@@ -1,5 +1,14 @@
 Left4Fix
 ========
+[![build](https://github.com/spumer/Left4Fix/actions/workflows/build.yaml/badge.svg)](https://github.com/spumer/Left4Fix/actions/workflows/build.yaml)
 
 Extension for SourceMod written on C++ and fix major bug on servers more than 8 players: incorrect completion score calculation.
-Main thread on the forum: http://forums.alliedmods.net/showthread.php?t=219774
+Main thread on the forum: http://forums.alliedmods.net/showthread.php?t=219774
+
+## How to get latest build?
+ - Log in into Github
+ - Go to to [build actions](https://github.com/spumer/Left4Fix/actions/workflows/build.yaml)
+ - Choose latest successful workflow
+ - Scroll down to "Artifacts" (if you are not logged in it's not available)
+
+![image](https://user-images.githubusercontent.com/735150/129475800-ddc2c482-554a-4cb8-881e-08d6c09bbc1a.png)