Regroup all Exclusive keyboard in one directory

To reduce clutter in the `keyboards/` directory, this patch moves all
keyboards definitions for Exclusive boards to its own subdirectory.

keyboards/exclusive/e6v2/le/keymaps/johu/readme.md

@@ -0,0 +1,40 @@
+# johu's E6-V2 Last Edition (LE) HHKB
+Make example for this keyboard (after setting up your build environment):
+```bash
+$ make e6v2/le:johu
+```
+
+Or to make and flash:
+```bash
+$ make e6v2/le:johu:dfu
+```
+
+See the [build environment setup] and the [make instructions] for more
+information. Brand new to QMK? Start with our [Complete Newbs Guide].
+
+## Layer 0: Base Layer
+* HHKB Qwerty layout plus some specials:
+  * The Space key sends `Space` when tapped, toggles to *Space FN Layer* when held
+  * [Grave Escape]
+  * The Ctrl key sends `Esc` when tapped, `Ctrl` when held
+  * The Tab key sends `Tab` when tapped, [Hyper] (`Super+Ctrl+Alt+Shift`) when held
+  * The right Shift key sends `Enter` when tapped, `Shift` when held
+
+## Layer 1: Function Layer
+* Default HHKB function layer includig the iconic diamond arrow cluster
+* Multimedia controls
+
+## Layer 2: Space FN Layer
+* VIM style arrow cluster
+* Multimedia controls
+
+## Layer 3: Control Layer
+* Reset button
+* RGB controls
+* Caps Lock
+
+[build environment setup]: https://docs.qmk.fm/#/getting_started_build_tools
+[make instructions]: https://docs.qmk.fm/#/getting_started_make_guide
+[Complete Newbs Guide]: https://docs.qmk.fm/#/newbs
+[Grave Escape]: https://beta.docs.qmk.fm/features/feature_grave_esc
+[Hyper]: http://brettterpstra.com/2012/12/08/a-useful-caps-lock-key