Add documentation on building FileScraper docs

docs/file-scrapers.md

@@ -0,0 +1,71 @@
+# File Scraper Reference
+
+This lists the docs that use `FileScraper` and instructions for building some of them.
+
+If you open a PR to update one of these docs, please add/fix the instructions.
+
+## C
+
+Download the HTML book from https://en.cppreference.com/w/Cppreference:Archives
+and copy `reference/en/c` from the ZIP file into `/path/to/devdocs/docs/c`.
+
+## C++
+
+Download the HTML book from https://en.cppreference.com/w/Cppreference:Archives
+and copy `reference/en/cpp` from the ZIP file into `/path/to/devdocs/docs/cpp`.
+
+## Dart
+
+Click the “API docs” link under the “Stable channel” header on
+https://www.dartlang.org/tools/sdk/archive. Rename the expanded ZIP to `dart~2`
+and put it in `/path/to/devdocs/docs/`
+
+## Django
+
+Go to https://docs.djangoproject.com/, select the version from the
+bubble in the bottom-right corner, then download the HTML version from the sidebar.
+
+## Erlang
+
+Go to https://www.erlang.org/downloads and download the HTML documentation file.
+
+## Gnu
+
+### GCC
+### GNU Fortran
+
+## NumPy
+
+## OpenJDK
+
+## Perl
+
+## PHP
+
+## Python
+
+## RDoc
+
+### Nokogiri
+### Ruby / Minitest
+### Ruby on Rails
+### Ruby
+
+## Salt Stack
+
+Replace `2019.2` with the correct tag.
+
+```sh
+git clone https://github.com/saltstack/salt.git --branch 2019.2 --depth 1
+cd salt/doc
+pip install sphinx
+make html
+```
+
+The generated html is in `salt/doc/_build/html`. Copy it to
+
+## Scala
+
+See `lib/docs/scrapers/scala.rb`
+
+## SQLite

lib/docs/scrapers/dart.rb

@@ -20,8 +20,6 @@ module Docs
       Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
     HTML
 
-    # Download the documentation from https://www.dartlang.org/tools/sdk/archive
-
     version '2' do
       self.release = '2.5.0'
       self.base_url = "https://api.dart.dev/stable/#{release}/"

lib/docs/scrapers/salt_stack.rb

@@ -1,13 +1,5 @@
 module Docs
   # The official documentation website is heavily rate-limited
-  #
-  # The documentation can be generated like this (replace 2019.2 with the correct tag):
-  # $ git clone https://github.com/saltstack/salt.git --branch 2019.2 --depth 1
-  # $ cd salt/doc
-  # $ pip install sphinx
-  # $ make html
-  #
-  # The generated html can be found in salt/doc/_build/html
   class SaltStack < FileScraper
     self.type = 'simple'
     self.slug = 'saltstack'