Add man page for llvm-readobj

llvm-svn: 179244
diff --git a/llvm/docs/CommandGuide/index.rst b/llvm/docs/CommandGuide/index.rst
index ac8a944..b3b4bc3 100644
--- a/llvm/docs/CommandGuide/index.rst
+++ b/llvm/docs/CommandGuide/index.rst
@@ -50,3 +50,4 @@
    tblgen
    lit
    llvm-build
+   llvm-readobj