updated markdown generation command

Author: fracpete

RELEASE.md

@@ -3,7 +3,7 @@ PyPi
 
 Preparation:
 
-* update all help files (`img-help -f markdown -o plugins -l INFO`)
+* update all help files (`img-help -f markdown -o plugins -i README.md -l INFO`)
 * update the help screen of `img-convert` in `README.md` to have the latest list of plugins
 * increment version in `setup.py`
 * add new changelog section in `CHANGES.rst`
@@ -15,9 +15,9 @@ Commands for releasing on pypi.org (requires twine >= 1.8.0):
 ```
 find -name "*~" -delete
 rm dist/*
-./venv/bin/python setup.py clean
-./venv/bin/python setup.py sdist
-./venv/bin/twine upload dist/*
+python3 setup.py clean
+python3 setup.py sdist
+twine upload dist/*
 ```