Merge pull request #31502 from CodaFi/rst-in-peace

[Gardening] Miscellaneous Documentation Conversions

Author: CodaFi

README.md

@@ -338,7 +338,7 @@ See [docs/Testing.md](docs/Testing.md), in particular the section on [lit.py](do
 
 Be sure to look through the [docs](https://github.com/apple/swift/tree/master/docs)
 directory for more information about the compiler. In particular, the documents
-titled [Debugging the Swift Compiler](docs/DebuggingTheCompiler.rst) and
+titled [Debugging the Swift Compiler](docs/DebuggingTheCompiler.md) and
 [Continuous Integration for Swift](docs/ContinuousIntegration.md) are very
 helpful to understand before submitting your first PR.
 

docs/CompilerPerformance.md

@@ -83,8 +83,8 @@ The set of jobs that are run, and the way they spend their time, is itself
 highly dependent on **compilation modes**. Information concerning those modes
 that's relevant to compilation performance is recounted in the following
 section; for more details on the driver, see [the driver docs](Driver.md), as
-well as docs on [driver internals](DriverInternals.rst)
-and [driver parseable output](DriverParseableOutput.rst).
+well as docs on [driver internals](DriverInternals.md)
+and [driver parseable output](DriverParseableOutput.md).
 
 After discussing compilation modes in the following section, we'll also touch on
 large-scale variation in workload that can occur _without_ obvious hotspots, in
@@ -1143,7 +1143,7 @@ driver. These files contain the driver's summary-view of the dependencies
 between entities defined and referenced in each source file; it is from these
 files that the driver decides when a file "needs" to be rebuilt because it
 depends on another file that needs to be rebuilt, and so on transitively. The
-file format is [documented here](DependencyAnalysis.rst).
+file format is [documented here](DependencyAnalysis.md).
 
 ### Finding areas in need of general improvement