Fix Planck and Preonic builds (#5658)

* Planck: Copy contents of Planck rules.mk to each revision

* Planck: Delete Planck rules.mk

* Planck: Concatenate duplicate rules

Concatenate rules that are set and then overridden into one setting.

* Preonic: Copy contents of Preonic rules.mk to each revision

* Preonic: Delete Preonic rules.mk

* Preonic: Concatenate duplicate rules

Concatenate rules that are set and then overridden into one setting.

* Planck: Delete non-specific Bootloader settings from revs. 1 and 2

Deleted BOOTLOADER setting code block, as the checks were only valid for revs. 3-5 and the Planck Light.

Neither Planck rev1 or rev2 set the bootloader via rules.mk, so there's no setting of BOOTLOADER in their rules.mk files.

* Preonic: Fix BOOTLOADER settings code blocks

* Preonic: delete extra blank lines from rules.mk files

* Preonic: delete AVR-type hardware config blocks from rev3

* Update Planck and Preonic readme files

- update Hardware Supported
- update/add Install Examples
- update Docs paragraph

* Enable Bootmagic Lite where it is disabled

Enabled Bootmagic Lite for:

- Planck Light
- Planck revs. 1-5
- Preonic revs. 1 and 2

* Remove `planck_grid` from LAYOUTS rule for all Planck revisions

Community has landed on `ortho_4x12`, which is already set; `planck_grid` is redundant.

1 files changed, 4 insertions, 3 deletions

diff --git a/keyboards/planck/readme.md b/keyboards/planck/readme.md
index 083279e8a6..94b256c745 100644
--- a/keyboards/planck/readme.md
+++ b/keyboards/planck/readme.md
@@ -6,7 +6,7 @@ Planck
 A compact 40% (12x4) ortholinear keyboard kit made and sold by OLKB and Massdrop. [More info on qmk.fm](http://qmk.fm/planck/)
 
 Keyboard Maintainer: [Jack Humbert](https://github.com/jackhumbert)  
-Hardware Supported: Planck PCB rev1, rev2, rev3, rev4, Teensy 2.0  
+Hardware Supported: Planck PCB rev1, rev2, rev3, rev4, rev5, rev6; Planck Light  
 Hardware Availability: [OLKB.com](https://olkb.com), [Massdrop](https://www.massdrop.com/buy/planck-mechanical-keyboard?mode=guest_open)
 
 Make example for this keyboard (after setting up your build environment):
@@ -15,6 +15,7 @@ Make example for this keyboard (after setting up your build environment):
 
 Install examples:
 
-    make planck/rev6:default:dfu-util
+    make planck/rev5:default:dfu         # For Planck rev5 or earlier and Planck Light
+    make planck/rev6:default:dfu-util    # For Planck rev6
 
-See [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) then the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information.
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).