doc: use common style

Use a common style for this section
that I use in my other Go open source projects.

Author: croaky

README.md

@@ -69,9 +69,14 @@ for a PTY interface.
 ## Developing
 
 ```bash
-go test ./...                         # run tests
-go vet ./...                          # static checks
-goimports -local "$(go list -m)" -w . # format imports
+# checks
+goimports -local "$(go list -m)" -w .
+go test ./...
+go vet ./...
+
+# commit
+git add -A
+git commit -m "proc: add new feature" # commit with prefix, imperative mood, hard-wrap 72 cols
 ```
 
 ## License