Implements new hold/tap flavor, tap-unless-interrupted
Adds tests
Adds docs

* Add optional `hold-trigger-key-positions` hold-tap configuration
* Leverage configuration for decision making around when to trigger
  hold decision in hold-taps.
* Add docs for new configuration.
* Tests for the new config/decision logic. 

tapping_term_ms -> tapping-term-ms
quick_tap_ms -> quick-tap-ms

The old style works, although it's deprecated.

Tap-and-hold a hold-tap to hold the tap behavior so it can repeat.
After a tap, if the same key is pressed within `quick_tap_ms`, the
tap behavior is always picked.

This is useful for things like `&ht LSHFT BACKSPACE` where holding
the backspace is required.

Implements #288.

when quick-release is enabled, the sticky key is released immediately after another key is pressed

closes #85

Does not include boards and shields.

Changes made with regex plus some manual tweaks.

Find:
/(?:(?<!#!\/bin\/sh\n)(?:^#\n))*^#.*?[Cc]opyright.*?(\d{4}) *([0-9A-z,_\- ]+).*?\n(?:^#\n)*^#.*?SPDX-License-Identifier:? *(.+) *?\n(?:^#\n)*/gm

Replace:
# Copyright (c) $1 $2
# SPDX-License-Identifier: $3

PR: #564