Move linter documentation into separate files

doc/ale-rust.txt

@@ -0,0 +1,60 @@
+===============================================================================
+ALE Rust Integration                                         *ale-rust-options*
+                                                         *ale-integration-rust*
+
+-------------------------------------------------------------------------------
+Integration Information
+
+  Since Vim does not detect the rust file type out-of-the-box, you need the
+  runtime files for rust from here: https://github.com/rust-lang/rust.vim
+
+  Note that there are two possible linters for rust files:
+
+  1. rustc -- The Rust compiler is used to check the currently edited file.
+     So, if your project consists of multiple files, you will get some errors
+     when you use e.g. a struct which is defined in another file. You can use
+     |g:ale_rust_ignore_error_codes| to ignore some of these errors.
+  2. cargo -- If your project is managed by Cargo, the whole project is
+     checked. That means that all errors are properly shown, but cargo can
+     only operate on the files written on disk. That means it is highly
+     recommended to turn off |g:ale_lint_on_text_changed| and to turn on
+     |g:ale_lint_on_save| in your vimrc file.
+
+  Only cargo is enabled by default. To switch to using rustc instead of cargo,
+  configure |g:ale_linters| appropriately: >
+
+  " See the help text for the option for more information.
+  let g:ale_linters = {'rust': ['rustc']}
+<
+
+  Also note that rustc 1.12. or later is needed.
+
+
+-------------------------------------------------------------------------------
+cargo                                                          *ale-rust-cargo*
+
+g:ale_rust_cargo_use_check                         *g:ale_rust_cargo_use_check*
+
+  Type: |Number|
+  Default: `1`
+
+  When set to `1`, this option will cause ALE to use "cargo check" instead of
+  "cargo build". "cargo check" is supported since version 1.16.0 of Rust.
+
+
+-------------------------------------------------------------------------------
+rustc                                                          *ale-rust-rustc*
+
+g:ale_rust_ignore_error_codes                   *g:ale_rust_ignore_error_codes*
+
+  Type: |List| of |String|s
+  Default: []
+
+  This variable can contain error codes which will be ignored. For example, to
+  ignore most errors regarding failed imports, put this in your .vimrc
+  >
+  let g:ale_rust_ignore_error_codes = ['E0432', 'E0433']
+
+
+-------------------------------------------------------------------------------
+  vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl: