go: Add info how to work with the new Go version

Signed-off-by: Tatiana Nesterenko <[email protected]>

Author: tatiana-nspcc

go.md

@@ -0,0 +1,24 @@
+# Working with Go language versions in project
+
+Upon the release of a new version of Go, all repositories are updated
+according to the following conditions:
+* The minimum supported version of Go is set to two versions back from 
+the previous one. (For example, upon the release of Go 1.22, the minimum 
+version becomes 1.20.)
+* All dependency packages are updated (sometimes, according to project 
+requirements, some deprecated package methods may be updated as well.)
+* Go versions in GitHub workflows are also updated as follows:
+
+  1. Testing is performed on the last three versions of Go (in the example
+  mentioned above, this would be `[ '1.20', '1.21', '1.22' ]`).
+  2. For build and cover jobs, the latest version should be used (in the 
+  example mentioned above, this would be 1.22). 
+  3. If there are new versions of GitHub actions, they can also be updated 
+  (for example, actions/checkout, actions/setup-go, actions/upload-artifact, 
+  etc.).
+  4. The Go version for the linter equals the minimum supported version and 
+  is usually taken from the `go.mod` file by specifying in the *.yml file:
+  ```        
+  with:
+    go-version-file: 'go.mod'
+  ```