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.

misc/themes/run.solar.light

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+for theme in $PWD/../../rc/solarized-light-256.theme
+do
+  cat <<EOF >x
+data.location=.
+confirmation=off
+detection=off
+_forcecolor=on
+default.height=24
+verbose=off
+include $theme
+EOF
+
+  echo "--- $theme -----------------------------------------------------"
+  echo '$ task color legend'
+  task rc:x color legend
+  echo '$ task list'
+  task rc:x list
+  echo '$ task summary'
+  task rc:x summary
+  echo '$ task ghistory'
+  task rc:x ghistory
+  echo '$ task calendar'
+  task rc:x calendar
+  echo '$ task burndown.daily'
+  task rc:x burndown.daily
+done