Decimal time face (#260)

* Update movement_faces.h

adding decimal_time_face.h to build

* Decimal Time, a new clock face

This face presents the current time as hours and hundredths of an hour.

* add decimal time to Makefile

movement/watch_faces/clock/decimal_time_face.h

@@ -0,0 +1,72 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2023 Curtis J. Brown <mrbrown8@juno.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef DECIMAL_TIME_FACE_H_
+#define DECIMAL_TIME_FACE_H_
+
+#include "movement.h"
+
+/*
+ * DECIMAL TIME FACE
+ * 
+ * This face presents the current time as hours and hundredths of an hour. Every hundreth of an hour, or "centihour", 
+ * occurs every 36 seconds. Because they range from 0 to 99, centihours, in the seventies range, will be displayed with a lowercase 7.
+ * 
+ * See https://en.wikipedia.org/wiki/Decimal_time#Decimal_hours
+ *  
+ * This method of timekeeping is used by the United States Postal Service.
+ * http://www.branch38nalc.com/sitebuildercontent/sitebuilderfiles/CONVERSION_TABLE_TIME.pdf
+ * https://postalemployeenetwork.com/time-conversion-print.htm
+ * 
+ * This method may be used by other organizations as well
+ * https://www.labor.nc.gov/workplace-rights/employer-responsibilities/time-conversion-chart-minutes-decimal-hours
+ * https://uh.edu/office-of-finance/payroll/time_conversion_chart_minutes_to_decimalhours.pdf
+ * https://www.placer.ca.gov/DocumentCenter/View/3860/Decimals-to-Minutes-Conversion-Table-PDF
+ * https://hr.colostate.edu/minute-to-decimal-conversion-chart/
+ * 
+ * Many thanks go to Joey Castillo for making this project happen.
+ * 
+ */
+
+typedef struct {
+    bool chime_enabled;            // did the user enable hourly chime for this face? 
+    uint8_t features_to_show : 2 ; // what features are to be displayed?
+} decimal_time_face_state_t;
+
+void decimal_time_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr);
+void decimal_time_face_activate(movement_settings_t *settings, void *context);
+bool decimal_time_face_loop(movement_event_t event, movement_settings_t *settings, void *context);
+void decimal_time_face_resign(movement_settings_t *settings, void *context);
+// void decimal_time_face_wants_background_task();
+
+
+#define decimal_time_face ((const watch_face_t){ \
+    decimal_time_face_setup, \
+    decimal_time_face_activate, \
+    decimal_time_face_loop, \
+    decimal_time_face_resign, \
+    NULL, \
+})
+
+#endif // DECIMAL_TIME_FACE_H_