[mypyc] Update README and add wiki links (#18463)

Remove stale content and add various links.

Author: JukkaL

mypyc/README.md

@@ -1,133 +1,12 @@
 mypyc: Mypy to Python C Extension Compiler
 ==========================================
 
-**NOTE: We are in the process of moving the mypyc README to the**
-**[mypyc repository](https://github.com/mypyc/mypyc)**
+For the mypyc README, refer to the [mypyc repository](https://github.com/mypyc/mypyc). The mypyc
+repository also contains the mypyc issue tracker. All mypyc code lives
+here in the mypy repository.
 
-**This may be out of date!**
+Source code for the mypyc user documentation lives under
+[mypyc/doc](./doc).
 
-Mypyc is a compiler that compiles mypy-annotated, statically typed
-Python modules into CPython C extensions. Currently our primary focus
-is on making mypy faster through compilation -- the default mypy wheels
-are compiled with mypyc.  Compiled mypy is about 4x faster than
-without compilation.
-
-Mypyc compiles what is essentially a Python language variant using "strict"
-semantics. This means (among some other things):
-
- * Most type annotations are enforced at runtime (raising ``TypeError`` on mismatch)
-
- * Classes are compiled into extension classes without ``__dict__``
-   (much, but not quite, like if they used ``__slots__``)
-
- * Monkey patching doesn't work
-
- * Instance attributes won't fall back to class attributes if undefined
-
- * Also there are still a bunch of bad bugs and unsupported features :)
-
-Compiled modules can import arbitrary Python modules, and compiled modules
-can be used from other Python modules.  Typically mypyc is used to only
-compile modules that contain performance bottlenecks.
-
-You can run compiled modules also as normal, interpreted Python
-modules, since mypyc targets valid Python code. This means that
-all Python developer tools and debuggers can be used.
-
-macOS Requirements
-------------------
-
-* macOS Sierra or later
-
-* Xcode command line tools
-
-* Python 3.5+ from python.org (other versions are untested)
-
-Linux Requirements
-------------------
-
-* A recent enough C/C++ build environment
-
-* Python 3.5+
-
-Windows Requirements
---------------------
-
-* Windows has been tested with Windows 10 and MSVC 2017.
-
-* Python 3.5+
-
-Quick Start for Contributors
-----------------------------
-
-First clone the mypy git repository:
-
-    $ git clone https://github.com/python/mypy.git
-    $ cd mypy
-
-Optionally create a virtualenv (recommended):
-
-    $ python3 -m venv <directory>
-    $ source <directory>/bin/activate
-
-Then install the dependencies:
-
-    $ python3 -m pip install -r test-requirements.txt
-
-Now you can run the tests:
-
-    $ pytest -q mypyc
-
-Look at the [issue tracker](https://github.com/mypyc/mypyc/issues)
-for things to work on. Please express your interest in working on an
-issue by adding a comment before doing any significant work, since
-there is a risk of duplicate work.
-
-Note that the issue tracker is hosted on the mypyc GitHub project, not
-with mypy itself.
-
-Documentation
--------------
-
-We have some [developer documentation](doc/dev-intro.md).
-
-Development Status and Roadmap
-------------------------------
-
-These are the current planned major milestones:
-
-1. [DONE] Support a smallish but useful Python subset. Focus on compiling
-   single modules, while the rest of the program is interpreted and does not
-   need to be type checked.
-
-2. [DONE] Support compiling multiple modules as a single compilation unit (or
-   dynamic linking of compiled modules).  Without this inter-module
-   calls will use slower Python-level objects, wrapper functions and
-   Python namespaces.
-
-3. [DONE] Mypyc can compile mypy.
-
-4. [DONE] Optimize some important performance bottlenecks.
-
-5. [PARTIALLY DONE] Generate useful errors for code that uses unsupported Python
-   features instead of crashing or generating bad code.
-
-6. [DONE] Release a version of mypy that includes a compiled mypy.
-
-7.
-    1. More feature/compatibility work. (100% compatibility with Python is distinctly
-       an anti-goal, but more than we have now is a good idea.)
-    2. [DONE] Support compiling Black, which is a prominent tool that could benefit
-       and has maintainer buy-in.
-       (Let us know if you maintain another Python tool or library and are
-       interested in working with us on this!)
-    3. More optimization! Code size reductions in particular are likely to
-       be valuable and will speed up mypyc compilation.
-
-8.  We'll see! Adventure is out there!
-
-Future
-------
-
-We have some ideas for
-[future improvements and optimizations](doc/future.md).
+Mypyc welcomes new contributors! Refer to our
+[developer documentation](./doc/dev-intro.md) for more information.

mypyc/doc/dev-intro.md

@@ -4,6 +4,14 @@ This is a short introduction aimed at anybody who is interested in
 contributing to mypyc, or anybody who is curious to understand how
 mypyc works internally.
 
+## Developer Documentation in the Wiki
+
+We have more mypyc developer documentation in our
+[wiki](https://github.com/python/mypy/wiki/Developer-Guides).
+
+For basic information common to both mypy and mypyc development, refer
+to the [mypy wiki home page](https://github.com/python/mypy/wiki).
+
 ## Key Differences from Python
 
 Code compiled using mypyc is often much faster than CPython since it