* Fix Pulse4k info.json LAYOUT name
* Add missing functions to fix configurator
Add empty encoder functions to the keyboard code, as the configurator doesn't see the keymap defined functions at first.
To be able to override these functions, they are marked as 'weak'.
* Rework encoder functions another time
Default implementation is now provided as part of the keyboard, but they can still be overriden within the keymap (template is commented out by default)
While this was historically a valid possibility, nowadays, it reads
kinda weird, and the [Oxford Dictionaries Online suggests to avoid it](https://english.stackexchange.com/a/56010).
Thus, I removed it everywhere I found it.
* Add Pulse 4k, a macropad by Maxr1998
* Some config tweaks
* Remove image note
* Add license headers
* Fix media keys
* Remove Play/pause again as it doesn't work on Linux
* Make some keys more accessible, prevent mistypings
* Add "Gaming" layer which maps L-Ctrl to space (left-handed jumping compatibility-mode for all games)