Updating Example configuration to override depth (#1519)

This should match the updated procedure introduced in
https://github.com/woodpecker-ci/plugin-git/pull/48

docs/docs/20-usage/20-pipeline-syntax.md

@@ -672,6 +672,7 @@ Example configuration to override depth:
    git:
      image: woodpeckerci/plugin-git
 +    settings:
++      partial: false
 +      depth: 50
 ```
 

docs/versioned_docs/version-0.15/20-usage/20-pipeline-syntax.md

@@ -428,6 +428,7 @@ Example configuration to override depth:
    git:
      image: woodpeckerci/plugin-git
 +    settings:
++      partial: false
 +      depth: 50
 ```