Creates a layouts/ folder for keymaps shared between keyboards (#1609)

* include variables and .h files as pp directives

* start layout compilation

* split ergodoxes up

* don't compile all layouts for everything

* might seg fault

* reset layouts variable

* actually reset layouts

* include rules.mk instead

* remove includes from rules.mk

* update variable setting

* load visualizer from path

* adds some more examples

* adds more layouts

* more boards added

* more boards added

* adds documentation for layouts

* use lowercase names for LAYOUT_

* add layout.json files for each layout

* add community folder, default keymaps for layouts

* touch-up default layouts

* touch-up layouts, some keyboard rules.mk

* update documentation for layouts

* fix up serial/i2c switches

1 files changed, 18 insertions, 0 deletions

diff --git a/build_layout.mk b/build_layout.mk
new file mode 100644
index 000000000..beb1cb662
--- /dev/null
+++ b/build_layout.mk
@@ -0,0 +1,18 @@
+LAYOUTS_PATH := layouts
+LAYOUTS_REPOS := $(patsubst %/,%,$(sort $(dir $(wildcard $(LAYOUTS_PATH)/*/))))
+
+define SEARCH_LAYOUTS_REPO
+    LAYOUT_KEYMAP_PATH := $$(LAYOUTS_REPO)/$$(LAYOUT)/$$(KEYMAP)
+    LAYOUT_KEYMAP_C := $$(LAYOUT_KEYMAP_PATH)/keymap.c
+    ifneq ("$$(wildcard $$(LAYOUT_KEYMAP_C))","")
+        -include $$(LAYOUT_KEYMAP_PATH)/rules.mk
+        KEYMAP_C := $$(LAYOUT_KEYMAP_C)
+        KEYMAP_PATH := $$(LAYOUT_KEYMAP_PATH)
+    endif
+endef
+
+define SEARCH_LAYOUTS
+    $$(foreach LAYOUTS_REPO,$$(LAYOUTS_REPOS),$$(eval $$(call SEARCH_LAYOUTS_REPO)))
+endef
+
+$(foreach LAYOUT,$(LAYOUTS),$(eval $(call SEARCH_LAYOUTS)))
\ No newline at end of file