README.md: create link for jcstest.c

diff --git a/README.md b/README.md
index 670445f9bbf94c17f3ef6eeb578c90e583ee8a22..1d3c3da56a2f5526dcdea72666b5862290981cb2 100755 (executable)
--- a/README.md
+++ b/README.md
@@ -102,8 +102,9 @@ extensions at compile time with:
 
     #ifdef JCS_ALPHA_EXTENSIONS
 
-jcstest.c, located in the libjpeg-turbo source tree, demonstrates how to check
-for the existence of the colorspace extensions at compile time and run time.
+[jcstest.c](jcstest.c), located in the libjpeg-turbo source tree, demonstrates
+how to check for the existence of the colorspace extensions at compile time and
+run time.
 
 libjpeg v7 and v8 API/ABI Emulation
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