docs: update cog-quality link (#1256)

### Motivation

The link to the cog-quality documentation is broken. The documentation
has moved somewhere else.

### Modifications

Link to the correct location of the documentation

<!-- TODO: Attach screenshots if you changed the UI. -->

### Verification

<!-- TODO: Say how you tested your changes. -->

scripts/gdal/gdal_presets.py

@@ -70,7 +70,7 @@
     "-co",
     "overview_compress=webp",
     # When resampling overviews use lanczos
-    # see https://github.com/linz/basemaps/blob/master/docs/imagery/cog.quality.md
+    # see https://github.com/linz/basemaps/blob/master/docs/operator-guide/cog-quality.md
     "-co",
     "overview_resampling=lanczos",
     # Reduce quality of overviews to 90%