Use submodule for date lib

A directory has been renamed

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "src/libs/QCBOR"]
 	path = src/libs/QCBOR
 	url = https://github.com/laurencelundblade/QCBOR.git
+[submodule "src/libs/date"]
+	path = src/libs/date
+	url = https://github.com/HowardHinnant/date.git

src/CMakeLists.txt

@@ -652,14 +652,14 @@ set(INCLUDE_FILES
         drivers/Cst816s.h
         FreeRTOS/portmacro.h
         FreeRTOS/portmacro_cmsis.h
-        libs/date/includes/date/tz.h
-        libs/date/includes/date/chrono_io.h
-        libs/date/includes/date/date.h
-        libs/date/includes/date/islamic.h
-        libs/date/includes/date/iso_week.h
-        libs/date/includes/date/julian.h
-        libs/date/includes/date/ptz.h
-        libs/date/includes/date/tz_private.h
+        libs/date/include/date/tz.h
+        libs/date/include/date/chrono_io.h
+        libs/date/include/date/date.h
+        libs/date/include/date/islamic.h
+        libs/date/include/date/iso_week.h
+        libs/date/include/date/julian.h
+        libs/date/include/date/ptz.h
+        libs/date/include/date/tz_private.h
         displayapp/LittleVgl.h
         displayapp/lv_pinetime_theme.h
         systemtask/SystemTask.h
@@ -682,7 +682,7 @@ include_directories(
         ../
         libs/
         FreeRTOS/
-        libs/date/includes
+        libs/date/include
         libs/mynewt-nimble/porting/npl/freertos/include
         libs/mynewt-nimble/nimble/include
         libs/mynewt-nimble/porting/nimble/include

src/libs/date

@@ -0,0 +1 @@
+Subproject commit 9502bc27a3b32fa5759ea82a76c22551620ebcd2