feat: Add initial restructured text docstirng parsing

This implementation should be mostly complete.

Not implemented:
 - references: Not planned at this time
 - examples: I'm not aware of a standard format for this

Still needed:
 - more test:
   - Many of the error cases aren't currently covered
   - More full fixture test cases

To be cleaned up:
 - I'm not confident I got the types right for all of the data that comes in with the context
 - ParseContext works, but it is a bit awkward with the rest of the project using the dict

References: mkdocstrings#67

pyproject.toml

@@ -20,6 +20,8 @@ include = [
 
 [tool.poetry.dependencies]
 python = "^3.6"
+dataclasses = {version = "^0.7", python = "3.6"}
+typing-extensions = {version = "^3.7.4.3", python = "3.6 || 3.7"}
 
 coverage = {version = "^5.2.1", optional = true}
 invoke = {version = "^1.4.1", optional = true}

src/pytkdocs/loader.py

@@ -314,7 +314,7 @@ def __init__(
                 "and the option will be removed in v0.13. "
                 "Please update your paths to use a colon to delimit modules from other objects. "
                 "Read more at https://pawamoy.github.io/pytkdocs/#details-on-new_path_syntax",
-                PendingDeprecationWarning
+                PendingDeprecationWarning,
             )
 
     def get_object_documentation(self, dotted_path: str, members: Optional[Union[Set[str], bool]] = None) -> Object:

src/pytkdocs/parsers/docstrings/__init__.py

@@ -4,5 +4,6 @@
 
 from pytkdocs.parsers.docstrings.base import Parser
 from pytkdocs.parsers.docstrings.google import Google
+from pytkdocs.parsers.docstrings.restructured_text import RestructuredText
 
-PARSERS: Dict[str, Type[Parser]] = {"google": Google}
+PARSERS: Dict[str, Type[Parser]] = {"google": Google, "restructured-text": RestructuredText}