[x] Introduce ADR https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/Wikibase/+/592297/
[x] Monitor usage
[] Enable code sniffer rule
**Estimation of completion** (note: requires Bash, not Zsh or other sh):
```lang=sh
done=$(grep --exclude-dir={vendor,node_modules,.idea,.phan} --include=\*.php -rwl . -e strict_types | wc -l) &&
todo=$(grep --exclude-dir={vendor,node_modules,.idea,.phan} --include=\*.php -rwl . -e . | wc -l) &&
percent=$(bc <<< "scale=5; 100 * $done / $todo") &&
head=$(git -c core.abbrev=10 rev-parse --short HEAD) &&
LC_ALL=C printf '* %(%d %B %Y)T (%s) = %d/%d = %1.2f%%\n' -1 "$head" "$done" "$todo" "$percent"
```
* 15 March 2021 (a350b421f4) = 371/1856 = 19.99%
* 24 August 2020 (d742344560) = 178/1750 = 10.17%
* 19 August 2020 (32d9945e95) = 168/1740 = 9.66%
* 15 July 2020 (a8ab42ecda) = 151/1734 = 8.71%
* 16 June 2020 (5187137054) = 45/1738 = 2.59%
* 7 May 2020 (84da94209a) = 22/1719 = 1.28%
* 23 April 2020 (aca4c86cbe) = 1/1704 = 0.06%