docs: typo and formatting fixes in code of conduct and contributors guidelines (#1197)

* docs: fix link in code of conduct

* docs: fix typo in contrib guidelines

substrate/CODE_OF_CONDUCT.adoc

@@ -47,7 +47,4 @@ Project maintainers who do not follow or enforce the Code of Conduct in good fai
 
 == Attribution
 
-This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [http://contributor-covenant.org/version/1/4][version]
-
-[homepage]: http://contributor-covenant.org
-[version]: http://contributor-covenant.org/version/1/4/
+This Code of Conduct is adapted from the http://contributor-covenant.org[Contributor Covenant], version 1.4, available at http://contributor-covenant.org/version/1/4

substrate/CONTRIBUTING.adoc

 = Contributing
 
-`Substrate` projects is a **OPENISH Open Source Project**
+The `Substrate` project is an **OPENISH Open Source Project**
 
 == What?