Adding some links on SIL docs.

Author: LucianoPAlmeida

docs/SIL.rst

@@ -29,7 +29,7 @@ representation that can be used for code distribution, but it can also express
 target-specific concepts as well as LLVM can.
 
 For more information on developing the implementation of SIL and SIL passes, see
-SILProgrammersManual.md.
+`SILProgrammersManual.md <SILProgrammersManual.md>`_ .
 
 SIL in the Swift Compiler
 -------------------------

docs/SILProgrammersManual.md

@@ -2,7 +2,7 @@
 
 This document provides information for developers working on the
 implementation of SIL. The formal specification of the Swift
-Intermediate _Language_ is in SIL.rst. This is a guide to the internal
+Intermediate _Language_ is in [SIL.rst](SIL.rst). This is a guide to the internal
 implementation. Source comments normally provide this level of
 information as much as possible. However, some features of the
 implementation are spread out across the source base. This
@@ -176,6 +176,6 @@ PassManager and its available analyses.
 
 ## High Level SIL Optimizations
 
-HighLevelSILOptimizations.rst discusses how the optimizer imbues
+[HighLevelSILOptimizations.rst](HighLevelSILOptimizations.rst) discusses how the optimizer imbues
 certain special SIL types and SIL functions with higher level
 semantics.