make a gdb "restart" command that allows restarting without rebuilding

gdbinit

@@ -0,0 +1,6 @@
+# the jlink debugger seems to want a pause after reset before we tell it to start running
+define restart
+  monitor reset 
+  shell sleep 1
+  cont 
+end

platformio.ini

@@ -141,7 +141,11 @@ lib_deps =
   https://github.com/meshtastic/BQ25703A.git
 monitor_port = /dev/ttyACM1
 
+debug_extra_cmds =
+  source gdbinit
+
 ; Set initial breakpoint (defaults to main)
 debug_init_break =
 ;debug_init_break = tbreak loop
-;debug_init_break = tbreak Reset_Handler
+;debug_init_break = tbreak Reset_Handler
+