Content-filter

- Makes the library typed
- Makes the library comply with PEP 8 better
- Drops support for Python 3.4 and 3.5, making the new minimum supported version 3.6

These changes were made by parafoxia in PR 12.

New Features
- Include the actual find value of the word in the list output of the check
- Include the filter which the found word belongs to in the list output of the check

The module has now been converted to a class-based, object orientated structure. Naming conventions for functions have also been changed to comply with PEP8 standards. In addition to that, new documentation has been released, this time on Read the Docs. Moving forward, this will be the main supported version until v3 (if we get to v3). Support for v1 will be existent but minimal. All new changes and features will be on v2 and not v1.

The filter now can convert foreign and look-alike charaters to their visual qwerty charaters. This allows for a stronger level of filtering and makes it harder to bypass the filter. This release will be the last supported release of version 1 as version 2 will bring with it a new and improved infrastructure that will comply with PEP8 standards and be more object orientated.

New Features
* Converts foreign charaters to visual qwerty equivalents
* Converts look-alike charaters to their visual qwerty equivalents
* Removes non-printing charaters from string
* Adds setup function that is optionally called as an initialization of some of the data (automatically run on first message check if not called before checking)
* Adds indexes to output of checkMessageList

Added the ability for users to define weather a word needs to have a space before it or not for it to trigger the filter when using a custom JSON file. See the [README](https://github.com/MrDogeBro/content_filter#custom-json-file-structure) for more specifics on using that feature. Also updated Python versions to support Python 3.9.

Added the ability to update the list of words to filter for while python is running when using a custom JSON file. This is useful if you need to make changes to the JSON file while the python is running, but don't want to restart python or something else that would do the same thing.