Added some tips/tricks

Fixes #35

doc/tips.md

@@ -0,0 +1,18 @@
+Miscellanous tips and tricks
+============================
+
+
+## Crimper
+
+Can't find that 13.37 cm long dark olive green network cable that would go
+perfectly with your Rain Forest GMMK keycaps? Follow @jinchoung's tip and get a
+cable crimper:
+
+![Cable crimper](images/tips/crimper.jpg)
+
+## LED layer indication
+
+Want to indicate active layer using the rp2040-Zero built-in LED?
+I tried this and found it a bit annoying... If you want to try, there
+is some code here: https://github.com/tompi/qmk_firmware/blob/67aa22818e2be422abdb32fc918c2b6757137a4e/keyboards/cheapino/cheapino.c#L45
+Follow the firmware guide for compiling, and uncomment the layer code above.

readme.md

@@ -25,6 +25,8 @@ See the [firmware guide](doc/firmware.md) for how to build and customize keyboar
 The cheapino has vial support, or you can build your own QMK to customize EVERYTHING.
 Even the onboard RP2040-Zero LED is controllable by QMK...
 
+I added [a few tips and tricks here](doc/tips.md).
+
 ![12](images/12.jpg)
 ![2](images/2.jpg)
 ![9](images/9.jpg)