update intro page, add layer-tap docs and update hold-tap docs.

docs/docs/behavior/hold-tap.md

@@ -22,7 +22,11 @@ We call this the 'hold-preferred' flavor of hold-taps. While this flavor may wor
 
 ![Hold-tap comparison](../assets/hold-tap/comparison.png)
 
-### Configuration
+### Basic usage
+For basic usage, please see [mod-tap](./mod-tap.md) and [layer-tap](./layers.md) pages.
+
+
+### Advanced Configuration
 A code example which configures a mod-tap setting that works with homerow mods:
 
 ```
@@ -58,5 +62,5 @@ If this config does not work for you, try the flavor "tap-preferred" and a short
 
 If you want to use a tap-hold with a keycode from a different code page, you have to define another behavior with another "bindings" parameter.For example, if you want to use SHIFT and volume up, define the bindings like `bindings = <&kp>, <&cp>;`. Only single-argument behaviors are supported at the moment.
 
-#### Note
+#### Comparison to QMK
-Astute readers may notice similarities between the possible behaviors in ZMK and other firmware, such as QMK. The hold-preferred flavor works similar to the `HOLD_ON_OTHER_KEY_PRESS` setting. The 'balanced' flavor is similar to the `PERMISSIVE_HOLD` setting, and the `tap-preferred` flavor is similar to `IGNORE_MOD_TAP_INTERRUPT`.
+The hold-preferred flavor works similar to the `HOLD_ON_OTHER_KEY_PRESS` setting in QMK. The 'balanced' flavor is similar to the `PERMISSIVE_HOLD` setting, and the `tap-preferred` flavor is similar to `IGNORE_MOD_TAP_INTERRUPT`. 

docs/docs/behavior/layers.md

@@ -26,7 +26,7 @@ This allows you to use those defines, e.g. `LOWER` later in your keymap.
 
 ## Momentary Layer
 
-The "momentary layer" behavior allows you to enable a layer while a certain key is pressed. Immediately upon
+The "momentary layer" behavior enables a layer while a certain key is pressed. Immediately upon
 activation of the key, the layer is enabled, and immediately open release of the key, the layer is disabled
 again.
 
@@ -41,9 +41,25 @@ Example:
 &mo LOWER
 ```
 
+## Layer-tap
+
+The "layer-tap" behavior enables a layer when a key is held, and output another key when the key is only tapped for a short time. For more information on the inner workings of layer-tap, see [hold-tap](./hold-tap.md).
+
+### Behavior Binding
+- Reference: `&lt`
+- Parameter: The layer number to enable when held, e.g. `1`
+- Parameter: The keycode to send when tapped, e.g. `A`
+
+Example:
+
+```
+&lt LOWER SPC
+```
+
+
 ## Toggle Layer
 
-The "toggle layer" behavior allows you to enable a layer until the layer is manually disabled.
+The "toggle layer" behavior enables a layer until the layer is manually disabled.
 
 ### Behavior Binding
 

docs/docs/intro.md

@@ -7,31 +7,36 @@ sidebar_label: Introduction
 ZMK Firmware is an open source (MIT) keyboard
 firmware built on the [Zephyr™ Project](https://zephyrproject.org/) Real Time Operating System (RTOS).
 
-The goal is to provider a powerful, featureful keyboard firmware that is free
+The goal is to provide a powerful, featureful keyboard firmware that is free
 of licensing issues that prevent upstream BLE support as a first-class
 feature.
 
 ## Features
 
-At this point, ZMK is _missing_ more features than it has. Currently, the mostly working bits
+At this point, ZMK is still missing many features. Currently, the working bits
 include:
 
-- HID Over GATT (HOG) - This is the official term for BLE HID devices
+- Wireless connectivity via BLE HID Over GATT (HOG)
-- Keymaps and layers with basic keycodes
+- USB connectivity
-- Some initial work on one "behavior", Mod-Tap
+- Low active power usage
-- Basic HID over USB
+- Split keyboard support
-- Basic consumer (media) keycodes.
+- [Keymaps and layers](behavior/layers)
-- Basic OLED display logic
+- [Hold-tap](behavior/hold-tap) (which includes [mod-tap](behavior/mod-tap), [layer-tap](behavior/layers))
-- Basic Split support
+- [Basic HID over USB](behavior/key-press)
-- Encoders
+- [Basic consumer (media) keycodes](behavior/key-press#consumer-key-press)
+- [Encoders](feature/encoders)
+- Basic [OLED display support](feature/displays)
+- [RGB Underglow](feature/underglow)
 
 ## Missing Features
 
-- One Shot
+- One Shot Keys
-- Layer Tap
+- Combo keys
-- Complete split support
+- Macros
+- Complete split support (encoders and RGB are not supported on the 'peripheral' side)
 - Battery reporting
-- Low power mode
+- Low power sleep states
+- Low power mode (to toggle LEDs and screen off)
 - Shell over BLE
 
 ## Code Of Conduct