code: def check_mods_docs_readme():
      
  
      docs_mods = []
  
      readme_fn = os.path.join( os.path.dirname(config.MULTIQC_DIR), 'docs', 'README.md')
      if not os.path.isfile(readme_fn):
          if os.environ.get('TRAVIS_BUILD_DIR') is not None:
              readme_fn = os.path.join( os.environ.get('TRAVIS_BUILD_DIR'), 'docs', 'README.md')
          else:
              logger.warn("Can't check docs readme in lint test as file doesn't exist: {}".format(readme_fn))
              return None
      with open(readme_fn) as f:
          fm = next(yaml.load_all(f, Loader=yaml.SafeLoader))
  
      for section in fm['MultiQC Modules']:
          for name, fn in fm['MultiQC Modules'][section].items():
              # remove modules/ and .md
              docs_mods.append(fn[8:-3])
  
      # Check that installed modules are listed in docs/README.md
      for m in config.avail_modules.keys():
          if m not in docs_mods and m != 'custom_content':
              errmsg = "LINT: Module '{}' found in installed modules, but not docs/README.md".format(m)
              logger.error(errmsg)
              report.lint_errors.append(errmsg)
  
      # Check that modules in docs/README.md are installed
      for m in docs_mods:
          if m not in config.avail_modules.keys() and m != 'custom_content':
              errmsg = "LINT: Module '{}' found in docs/README.md, but not installed modules".format(m)
              logger.error(errmsg)
              report.lint_errors.append(errmsg)
docs: Check that all modules are listed in the YAML index
      at the top of docs/README.md