chore: use placeholder

docs/contributing_docs.md

@@ -10,8 +10,8 @@ We publish our documentation using Netlify.
 To include code snippets in the documentation, we use the [codeinclude plugin](https://github.com/rnorth/mkdocs-codeinclude-plugin), which uses the following syntax:
 
 &lt;!--codeinclude--&gt;<br/>
-&#91;Human readable title for snippet&#93;(./relative_path_to_example_code.go) block:someString<br/>
-&#91;Human readable title for snippet&#93;(./relative_path_to_example_code.go) inside_block:someString<br/>
+&#91;Human readable title for snippet&#93;(./relative_path_to_example_code.go) targeting_expression<br/>
+&#91;Human readable title for snippet&#93;(./relative_path_to_example_code.go) targeting_expression<br/>
 &lt;!--/codeinclude--&gt;<br/>
 
 Where each title snippet in the same `codeinclude` block would represent a new tab