Add table to readme with the current github action build configuration

Author: organom

readme.md

@@ -182,6 +182,19 @@ Please refer to extension located in https://github.com/ngs-lang/ngs-ipython-ext
 
 	make build
 
+Build is currently tested with the github action present in `.github/workflows/build.yml` and we currently test:
+
+| system        | gcc           | clang        |
+|---------------|---------------|--------------|
+| ubuntu 20.04  | 9, 10, 11     | 9, 10, 11    |
+| debian 11.1   | 9, 10         | 9, 11        |
+| centos 7      | 9, 10, 11     | ---          |
+| centos 8      | 9, 10, 11     | ---          |
+| macOS 10.15   | 9, 10, 11     | 10           |
+| amazonlinux 2 | default - 7.3 | default - 11 |
+| fedora 34     | default - 11  | default - 12 |
+| fedora 35     | default - 11  | default - 13 |
+
 ### Run
 
 	# If NGS is not installed (from the root of ngs project):