Add /faq/ section

[biodranik]

A taxonomy should be enabled to enable content categorization not only for faq but also for the news section and other future sections.

Each FAQ question + answer should have a separate markdown page for easier translation.

The root faq section should be an index page that combines all individual faq pages and groups them by the taxonomy (or maybe we need manual subcategories?).

Initial content can be taken from the organicmaps repo in data/faq.html.

An important new section is TTS instructions, there's unfinished #32 about it. For reference:
https://mapsme.zendesk.com/hc/en-us/articles/208628985-How-can-I-check-TTS-settings-on-my-Android-device-

[biodranik]

1. FAQ should be properly displayed for iOS, Android and desktop users. iOS users don't need Android instructions.
2. As we'll have images and videos, all FAQ items should not be visible at once. It implies either showing answers only after clicking on questions or splitting answers into small groups.
3. It should be easy to (re)generate a static HTML FAQ also to embed it into the iOS and Android app for offline use.
4. Each question should also have a separate page, a direct link for SEO and sharing with others.
5. Some articles are about several related topics and may be grouped/present in different taxonomy categories. The first category can be counted as the "main" one.
6. File structure should be easily translatable (a separate folder with index.md files for each question/answer).
7. The order of questions should be configurable and should allow insertions later.
8. Bonus: think about "Related questions/articles".

Considering the points above, the main FAQ page may group questions by functionality (no Android/iOS groups). Each question should be tagged by operating system(s) to properly show in /faq/android/ or /faq/ios/

[biodranik]

Let's try this FAQ structure on the website:

/faq/ shows a list of clickable questions/URLs grouped by the faq taxonomy (Map, General, Navigation, etc., we can improve it later). Clicking URLs opens /faq/how-to-build-a-route/ article with details.

A separate Operating System taxonomy with iOS, Android, Linux is applied to each related article. The main FAQ page contains direct links to these taxonomies to display all articles filtered by the operating system (/faq/android/).

Files can stored in content/faq/how-to-build-a-route/index.[lang.]md (path = question for SEO).
weight with a step 100 can be used to manually re-order articles.

@strump