[JIT] improve documentation (pytorch#57991)

Summary:
* Fix lots of links.
* Minor improvements for consistency, clarity or grammar.
* Update jit_python_reference to note the limitations on __exit__.
  (Related to pytorch#41420).
* Fix a comment in exit_transforms.cpp: removed the word "not" which
  made the comment say the opposite of the truth.

Pull Request resolved: pytorch#57991

Reviewed By: malfet

Differential Revision: D28522247

Pulled By: SplitInfinity

fbshipit-source-id: fc63a59d19ea6c89f957c9f7d451be17d1c5fc91

Author: garymm

aten/src/ATen/core/ivalue_inl.h

@@ -428,8 +428,9 @@ struct C10_EXPORT ivalue::Future final : c10::intrusive_ptr_target {
       // log errors and thats why we have this log here.
       std::string msg = c10::str(
           "Skipping setting following error on the Future since "
-          "it is already marked completed (this is not neccessarily "
-          "an error):\n", tryRetrieveErrorMessageInternal(eptr));
+          "it is already marked completed (this is not necessarily "
+          "an error):\n",
+          tryRetrieveErrorMessageInternal(eptr));
       if (eptr_) {
         msg += c10::str(
             ", \nOriginal exception:\n",
@@ -572,7 +573,7 @@ struct C10_EXPORT ivalue::Future final : c10::intrusive_ptr_target {
 
   // This method should be called before this future's value is used, as it
   // ensures that the CUDA streams that are "current" at the callsite properly
-  // synchonize with the value.
+  // synchronize with the value.
   void synchronizeWithCurrentStreams() {
     for (c10::Event& event : events_) {
       event.block(impl_.getStream(event.device()));

docs/source/jit_python_reference.rst

@@ -395,8 +395,8 @@ support in TorchScript. The categorizations are as follows:
      - Not Supported
      -
    * - `8.5. The with statement <https://docs.python.org/3/reference/compound_stmts.html#the-with-statement>`_
-     - Supported
-     -
+     - Partially Supported
+     - ``__exit__`` is always called with ``exc_type``, ``exc_value``, and ``traceback`` set to None, even if an exception was raised, and ``__exit__``'s return value is ignored.
    * - `8.6. Function definitions <https://docs.python.org/3/reference/compound_stmts.html#function-definitions>`_
      - Not Supported
      -