Consolidate in-repo documentation (#3143)

* move doc/misc to top level, add READMEs

* Move docs -> doc/devel

This also consolidates the _three_ documents describing (differently)
how to build Taskwarrior into a signle document.

doc/devel/rfcs/workweek.md

@@ -0,0 +1,29 @@
+---
+title: "Taskwarrior - Work Week Support"
+---
+
+## Work in Progress
+
+This design document is a work in progress, and subject to change.
+Once finalized, the feature will be scheduled for an upcoming release.
+
+
+# Work Week Support
+
+Taskwarrior supports the idea that a week starts on either a Sunday or a Monday, as determined by configuration.
+This was added eight years ago, simply for display purposes in the `calendar` report.
+Since then its use has propagated and it influences the `sow` date reference.0
+
+Further requests have been made to make this more flexible, so that the notion of 'weekend' can be defined.
+Furthermore, the idea that every week has a weekend has also been questioned.
+
+It has become clear that a `weekstart` setting, and the notion of a weekend are no longer useful.
+
+## Proposed Support
+
+One option is to allow the user to completely define a work week in the following way:
+
+    workweek=1,2,3,4,5
+
+With Sunday as day zero, this states that the work week is the typical Monday - Friday.
+From this setting, the meaning of `soww` and `eoww` can be determined, as well as `recur:weekday`.