Fix missing documentation for many clock faces:

* Move from .c to .h as needed for consistency.
* When missing from both, copy from pull request or wiki.
* When missing entirely, infer functionality from source code.

movement/watch_faces/clock/weeknumber_clock_face.h

@@ -25,6 +25,14 @@
 #ifndef WEEKNUMBER_CLOCK_FACE_H_
 #define WEEKNUMBER_CLOCK_FACE_H_
 
+/*
+ * WEEK-NUMBER WATCH FACE
+ *
+ * Same as simple clock, but has iso 8601 week number instead of seconds counter.
+ *
+ * Long-press ALARM to toggle the hourly chime.
+ */
+
 #include "movement.h"
 
 typedef struct {