add more hooks/linters (see also ci-templates#14)

     English language

   * checks the internal anchors and links using Nanoc

 * [Danger systems](https://danger.systems/ruby/) has a bunch of plugins which could be used to

   check documentation ([precious](https://github.com/houseabsolute/precious) and [pre-commit](https://pre-commit.com/) are similar wrappers)

   check documentation ([lefthook](https://github.com/evilmartians/lefthook), [precious](https://github.com/houseabsolute/precious), and

   [pre-commit](https://pre-commit.com/) are similar wrappers)

 * [textlint](https://textlint.github.io/): pluggable text linting approach recognizing markdown

 * [proselint](http://proselint.com/): grammar and style checkign

 * [languagetool](https://www.languagetool.org/): Grammar, Style and Spell Checker

 * [anorack](https://github.com/jwilk/anorack): spots errors based on phonemes

 * [redpen](https://redpen.cc/): huge JAR, can be noisy

 * [linkchecker](https://github.com/linkchecker/linkchecker/): can check links in HTML (anarcat is one of the

   maintainers), has many alternatives, see for example [lychee](https://github.com/lycheeverse/lychee)

   maintainers), has many alternatives, see for example [lychee](https://github.com/lycheeverse/lychee),

   [muffet](https://github.com/raviqqe/muffet), [hyperlink](https://github.com/untitaker/hyperlink), [more](https://gitlab.torproject.org/tpo/tpa/ci-templates/-/issues/14#note_2843661))

 * [forspell](https://github.com/kkuprikov/forspell): wrapper for hunspell, can deal with (Ruby, C, C++)

   source code, local dictionnaries

Note that we currently use [markdownlint][], the Ruby version, not the

Node version. This was primarily because anarcat dislikes Node more