Document SPIR-V binary and assembly file naming convention.

diff --git a/README.md b/README.md
index 743baeb..18f5368 100644 (file)
--- a/README.md
+++ b/README.md
@@ -149,6 +149,10 @@ There are three main entry points into the library.
 
 ## Command line tools
 
+Command line tools, which wrap the above library functions, are provided to
+assemble or disassemble shader files.  It's a convention to name SPIR-V
+assembly and binary files with suffix `.spvasm` and `.spv`, respectively.
+
 ### Assembler tool
 
 The assembler reads the assembly language text, and emits the binary form.