[Keymap] ericgebhart keymap and userspace updates (#15727)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Dasky <32983009+daskygit@users.noreply.github.com>
Co-authored-by: Drashna Jael're <drashna@live.com>

users/ericgebhart/caps_word.h

@@ -0,0 +1,35 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// Caps Word, activated by pressing both shift keys at the same time.
+//
+// This library implements "Caps Word", which is like conventional Caps Lock,
+// but automatically disables itself at the end of the word. This is useful for
+// typing all-caps identifiers like `MOD_MASK_ALT`.
+//
+// Caps Word is activated by pressing the left and right shift keys at the same
+// time. This way you don't need a dedicated key for using Caps Word. I've
+// tested that this works as expected with one-shot mods and Space Cadet Shift.
+// If your shift keys are mod-taps, activate Caps Word by holding both shift
+// mod-tap keys until the tapping term, release them, then begin typing.
+//
+// For full documentation, see
+// https://getreuer.info/posts/keyboards/caps-word
+
+#pragma once
+
+#include QMK_KEYBOARD_H
+
+bool process_caps_word(uint16_t keycode, keyrecord_t* record);