Remove HACKING.md

Half of this is outdated and the other half is questionable.

HACKING.md

@@ -1,24 +0,0 @@
-## Logging
-
-Use `sway_log(importance, fmt, ...)` to log. The following importances are
-available:
-
-* `WLR_DEBUG`: Debug messages, only shows with `sway -d`
-* `WLR_INFO`: Informational messages
-* `WLR_ERROR`: Error messages
-
-`sway_log` is a macro that calls `_sway_log` with the current filename and line
-number, which are written into the log with your message.
-
-## Assertions
-
-In the compositor, assertions *must not* be fatal. All error cases must be
-handled as gracefully as possible - crashing the compositor will make the user
-lose all of their work.
-
-Use `sway_assert(condition, fmt, ...)` to perform an assertion. This returns
-`condition`, which you must handle if false. An error will be logged if the
-assertion fails.
-
-Outside of the compositor (swaymsg, swaybar, etc), using `assert.h` is
-permitted.