docs: Fix a few typos (#606)

* docs: Fix a few typos

There are small typos in:
- doc/versioning.md
- src/components/ble/NimbleController.cpp
- src/libs/mynewt-nimble/CODING_STANDARDS.md
- src/libs/mynewt-nimble/docs/btshell/btshell_GAP.rst
- src/systemtask/SystemTask.cpp

Fixes:
- Should read `milliseconds` rather than `miliseconds`.
- Should read `unnecessary` rather than `uncesseray`.
- Should read `target` rather than `tharget`.
- Should read `project` rather than `projct`.
- Should read `preferred` rather than `prefered`.
- Should read `functioning` rather than `functionning`.
- Should read `forever` rather than `forver`.
- Should read `existing` rather than `exisiting`.

src/components/ble/NimbleController.cpp

@@ -126,7 +126,7 @@ void NimbleController::StartAdvertising() {
   //  ASSERT(res == 0);// TODO I've disabled these ASSERT as they sometime asserts and reset the mcu.
   // For now, the advertising is restarted as soon as it ends. There may be a race condition
   // that prevent the advertising from restarting reliably.
-  // I remove the assert to prevent this uncesseray crash, but in the long term, the management of
+  // I remove the assert to prevent this unnecessary crash, but in the long term, the management of
   // the advertising should be improve (better error handling, and advertise for 3 minutes after
   // the application has been woken up, for example.
 }