fix: Add Helping Verb to README

Because we all get by with a little help from our friends.

Author: evolvedmicrobe

README.md

@@ -61,7 +61,7 @@ Supported features are following:
 
 ### For library developer
 
-If you creating a library depending on this crate, we encourage you not to link any backend:
+If you are creating a library depending on this crate, we encourage you not to link any backend:
 
 ```toml
 [dependencies]