Screen-brightness-control

* Fix display information being overridden by `None` values

Added/Changed
* Added native desktop monitor control for Linux via `linux.I2C` class
* Add `get_methods` function
* Add `EDID.parse` method with massively improved EDID parsing capabilities
* Move generic, independent functions into `helpers.py`
* Remove some useless caching
Deprecated for removal in next release
* Deprecated `EDID.parse_edid` method
* Deprecated `linux.XBacklight` class (see [c9f798b](https://github.com/Crozzers/screen_brightness_control/commit/c9f798b54a1159f680d1759e363657ef7245ed2d) for reasoning)

* Change return types for `[set/get/fade]_brightness`. They will no longer return `int`, always `List[int]`
* Clean up `fade_brightness` internal error handling
* `linux.XBacklight` now raises `ValueError` if no valid output is received from the command
* Remove deprecated module level variable `method`
* More improvements to the documentation building toolchain

* Simplify `windows.VCP.iter_physical_monitors` `start` kwarg logic
* Actually bump `_version.py` version info this time

* Add missing variable deceleration in `windows.get_display_info`
* Move version info to `_version.py`
* New documentation tool-chain
* Deprecate module level `method` variable

* Fix 13 where some laptop displays were being returned by `windows.VCP.iter_physical_monitors`
* `windows.VCP.iter_physical_monitors` will now only return handles for monitors with the `win32con.DISPLAY_DEVICE_ATTACHED_TO_DESKTOP` StateFlag (see [this comment](https://github.com/Crozzers/screen_brightness_control/issues/13#issuecomment-956567787) for explanation)