Update README.md

Co-authored-by: davidlion <davidlion2@protonmail.com>

Author: Bill-hbrhbr

README.md

@@ -16,7 +16,7 @@ git submodule update --init --recursive
 ```
 
 # Building
-To build `ystdlib-cpp`:
+To build all targets in `ystdlib-cpp`:
 ```shell
 task build:target
 ```