A large migration of documentation over to mkdocs, and some rewrites. Some stuff (install information, basic supported systems, contributors, thanks) are still staying in README.md, and CONTRIBUTING.md is essentially duplicated right now. However, stuff like configuration and key/mouse bindings are now moved to mkdocs.
Some parts are still a bit WIP - it is definitely not done (documentation never seems to be...). However, it should be "good enough" for now, and I'm much happier working with the documentation in this form than trying to scroll through a giant endless README.md file. It also works much better for adding new documentation.
This PR accomplishes two things:
1. This PR aims to add mount_filter to the config file. This allows a user to filter their disk widget entries by the mount name as well; this was particularly a problem in trying to address #431.
2. A slight rework of how the filter system works due to the need of being able to manage two potentially conflicting filter sources, since the disk widget will now potentially filter on both the disk name and the mount name.
In regards to the second point, the new behaviour is as such:
1. Is the entry allowed through any filter? That is, does it match an entry in a filter where is_list_ignored is false? If so, we always keep this entry.
2. Is the entry denied through any filter? That is, does it match an entry in a filter where is_list_ignored is true? If so, we always deny this entry.
3. Anything else is allowed.
This main (breaking) change is really the third point. This would mean that temp_filter and net_filter, when set to allow listed entries with is_list_ignored = false, are kinda... useless, as a whitelist in the scenario of being the only filter is kinda pointless. But hopefully this shouldn't be a problem...?
Rewrite of the y-axis labeling and scaling for the network widget, along with more customization. This still has one step to be optimized (cache results so we don't have to recalculate the legend each time), but will be done in another PR for sake of this one being too large already.
Furthermore, this change adds linear interpolation at the 0 point in the case a data point shoots too far back - this seems to have lead to ugly gaps to the left of graphs in some cases, because the left hand limit was not big enough for the data point. We address this by grabbing values just outside the time range and linearly interpolating at the leftmost limit. This affects all graph widgets (CPU, mem, network).
This can be optimized, and will hopefully be prior to release in a separate change.
Adds users into the process widget (for Unix-based systems). This shows only in non-grouped modes, similar to state. Search is also supported.
In addition, a quick fix to prevent users from being in grouped mode when they tried to enter tree mode while grouped.
Adds a new option in the config file to filter out network interfaces. Also add the option to filter by whole words.
Interface follows that of the existing ones:
```toml
[net_filter]
is_list_ignored = false
list = ["virbr0.*"]
regex = true
case_sensitive = false
whole_word = false
```
