docs: fix contribution guide links [skip ci]

docs/code_formatting_rules.md

@@ -16,7 +16,8 @@ in `lnd` to help improve the overall readability.
 
 Blocks of code within `lnd` should be segmented into logical stanzas of
 operation. Such spacing makes the code easier to follow at a skim, and reduces
-unnecessary line noise. Coupled with the commenting scheme specified above,
+unnecessary line noise. Coupled with the commenting scheme specified in the
+[contribution guide](./code_contribution_guidelines.md#code-documentation-and-commenting),
 proper spacing allows readers to quickly scan code, extracting semantics quickly.
 Functions should _not_ just be laid out as a bare contiguous block of code.