RST: update parser and queries

- The directive type does not longer includes `::`.
- The content of the directives is not longer interpreted as rst,
  but it uses language injection for it.
- Fix a query to allow to capture targets without link.
- Reset the content of the math role so it can be highlighted by the
  injection instead.

Problems I found:

- Capturing the same node with @language and @content will raise an
  error.

  ```
  Error detected while processing FileType Autocommands for "*":
  E5108: Error executing lua /usr/share/nvim/runtime/lua/vim/treesitter/languagetree.lua:331: table index is nil
  ```

  Harcoding the language works, Using the offset predicate doesn't work
  either `(#offset! 0 0 1 0)` nor `(#offset! 0 0 0 5)`

- Generating the grammar using `tree-sitter-cli@0.17.x` breaks
  nvim-treesitter, `@0.16.9` works.

queries/rst/injections.scm

@@ -0,0 +1,47 @@
+(doctest_block) @python
+
+;; Directives with nested content
+
+((directive
+   name: (type) @_type
+   body: (body) @rst)
+ (#match?
+  @_type
+  "^(attention|caution|danger|error|hint|important|note|tip|warning|admonition)|(image|figure)|(topic|sidebar|line-block|parsed-literal|rubric|epigraph|highlights|pull-quote|compound|container)|(table|list-table)|(contents|sectnum|section-numbering|header|footer)|(target-notes)|(meta)|(replace|unicode|date)|(include|class|role|default-role|title|restructuredtext-test-directive)$"))
+
+;; Special directives
+
+;; TODO: using @language and @content on the same capture raises an error.
+;; ((directive
+;;    name: (type) @_type
+;;    body: (body) @language @content)
+;;  (#eq? @_type "code"))
+
+;; ((directive
+;;    name: (type) @_type
+;;    body: (body) @language @content)
+;;  (#eq? @_type "raw"))
+
+((directive
+   name: (type) @_type
+   body: (body) @latex)
+ (#eq? @_type "math"))
+
+((directive
+   name: (type) @_type
+   body: (body) @csv)
+ (#eq? @_type "csv-table"))
+
+;; Special roles - prefix
+
+((interpreted_text
+  (role) @_role
+  "interpreted_text" @latex)
+ (#eq? @_role ":math:"))
+
+;; Special roles - suffix
+
+((interpreted_text
+  "interpreted_text" @latex
+  (role) @_role)
+ (#eq? @_role ":math:"))