doc: adding estimated execution time

mawaregetsuka · mawaregetsuka · commit 3b18d8695ec4 · 2021-12-12T03:09:41.000+08:00
diff --git a/doc/guides/contributing/pull-requests.md b/doc/guides/contributing/pull-requests.md
@@ -251,7 +251,9 @@ And on Windows:
 > vcbuild test
 ```
 
-(See the [running tests][] section of Building guide for more details.)
+(This code might take more than an hour to execute on a PC, want to run a part
+of tests quickly or for more details see the [running tests][] section of Buil
+ding guide.)
 
 ### Step 7: Push
 
