Remove msg template section from readme file

Author: codingjoe

README.md

@@ -56,25 +56,6 @@ option `--diff [-d]` or `--git-diff [-g]`:
 git diff --unified=0 | relint my_file.py --diff
 ```
 
-### Custom message format
-
-Customize the output message format with the `--msg-template=<format string>` option.
-[Python format syntax](https://docs.python.org/3/library/string.html#formatstrings)
-is suported for the message template and the following fields are available:
-
-* `filename`
-  The name of the file being linted.
-
-* `line_no`
-  The line number of the match.
-
-* `match`
-  The matched text.
-
-* `test.*`
-  Any attribute of the test rule, e.g. `test.name` or `test.hint`.
-
-
 ### pre-commit
 
 You can automate the linting process by adding a