Fix redirects

Author: dstansby

docs/conf.py

@@ -83,10 +83,10 @@
 release = get_version("zarr")
 
 redirects = {
-     "docs/spec": "https://zarr-specs.readthedocs.io",
-     "docs/spec/v1": 'https://zarr-specs.readthedocs.io/en/latest/v1/v1.0.html',
-     "docs/spec/v2": "https://zarr-specs.readthedocs.io/en/latest/v2/v2.0.html",
-     "docs/spec/v3": "https://zarr-specs.readthedocs.io/en/latest/v3/core/v3.0.html",
+     "spec": "https://zarr-specs.readthedocs.io",
+     "spec/v1": 'https://zarr-specs.readthedocs.io/en/latest/v1/v1.0.html',
+     "spec/v2": "https://zarr-specs.readthedocs.io/en/latest/v2/v2.0.html",
+     "spec/v3": "https://zarr-specs.readthedocs.io/en/latest/v3/core/v3.0.html",
 }
 
 # The language for content autogenerated by Sphinx. Refer to documentation