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/complication/interval_face.c

@@ -22,8 +22,6 @@
  * SOFTWARE.
  */
 
-//-----------------------------------------------------------------------------
-
 #include <stdlib.h>
 #include <string.h>
 
@@ -33,57 +31,6 @@
 #include "watch_private_display.h"
 #include "watch_buzzer.h"
 
-/*
-    This face brings 9 customizable interval timers to the sensor watch,
-    to be used as hiit training device and/or for time management techniques.
-
-    - There are 9 interval timer slots, you can cycle through these with the
-      alarm button (short press). For each timer slot, a short "slideshow"
-      displaying the relevant details (like length of each phase - see below)
-      is shown.
-
-    - To start an interval timer, press and hold the alarm button.
-
-    - To pause a running timer, press the alarm button (short press).
-
-    - To completely abort a running timer, press and hold the alarm button.
-
-    - Press and hold the light button to enter settings mode for each interval
-      timer slot.
-
-    - Each interval timer has 1 to 4 phases of customizable length like so:
-      (1) prepare/warum up --> (2) work --> (3) break --> (4) cool down.
-      When setting up or running a timer, each of these phases is displayed by
-      the letters "PR" (prepare), "WO" (work), "BR" (break), "CD" (cool down).
-
-    - Each of these phases is optional, you can set the corresponding
-      minutes and seconds to zero. But at least one phase needs to be set, if
-      you want to use the timer.
-
-    - You can define the number of rounds either only for the work
-      phase and/or for the combination of work + break phase. Let's say you
-      want an interval timer that counts 3 rounds of 30 seconds work, 
-      followed by 20 seconds rest:
-            work 30s --> work 30s --> work 30s --> break 20s
-      You can do this by setting 30s for the "WO"rk phase and setting a 3
-      in the lower right hand corner of the work page. The "LAP" indicator
-      lights up at this position, to explain that we are setting laps here.
-      After that, set the "BR"eak phase to 20s and leave the rest as it is.
-
-    - If you want to set up a certain number of "full rounds", consisting
-      of work phase(s) plus breaks, you can do so at the "BR"eak page. The
-      number in the lower right hand corner determines the number of full
-      rounds to be counted. A "-" means, that there is no limit and the 
-      timer keeps alternating between work and break phases.
-
-    - This watch face comes with several pre-defined interval timers,
-      suitable for hiit training (timer slots 1 to 4) as well as doing
-      work according to the pomodoro principle (timer slots 5 to 6).
-      Feel free to adjust the timer slots to your own needs (or completely 
-      wipe them ;-)
-
-*/
-
 typedef enum {
     interval_setting_0_timer_idx,
     interval_setting_1_clear_yn,