Docs: Update docs/examples/00_README.txt.

doc/examples/00_README.txt

diff --git a/doc/examples/00_README.txt b/doc/examples/00_README.txt
index a3b9eaa..120e1eb 100644
--- a/doc/examples/00_README.txt
+++ b/doc/examples/00_README.txt
@@ -25,3 +25,7 @@
                                         a custom filter chain
                                         (x86 BCJ + LZMA2)
 
+    04_compress_easy_mt.c               Multi-threaded multi-call
+                                        compression using a compression
+                                        preset
+