add equations for floc filtration in clarifier and potential approach…

[monroews]

… for auto coag model. Also eliminate a few more html errors.

Pull request recommendations:

• [ ] Name your branch/PR your-development-type/short-description. Ex: feature/read-tiff-files
• [ ] Link to any relevant issue in the PR description. Ex: Resolves [gh-12], adds tiff file format support
• [ ] Provide context of changes.
• [ ] Provide relevant tests for your feature or bug fix.
• [ ] Provide or update documentation for any feature added by your pull request.

Thanks for contributing!