Fix grammar in README.md

Author: pogo59

README.md

@@ -19,7 +19,7 @@ Welcome to the LLVM project!
 
 The LLVM project has multiple components. The core of the project is
 itself called "LLVM". This contains all of the tools, libraries, and header
-files needed to process intermediate representations and converts it into
+files needed to process intermediate representations and convert them into
 object files.  Tools include an assembler, disassembler, bitcode analyzer, and
 bitcode optimizer.  It also contains basic regression tests.