chore: Prepare merge of postgrest-docs into postgrest main repo

This avoids some merge conflicts to allow git blame to detect renames properly.

docs/README.md

@@ -0,0 +1,20 @@
+# PostgREST documentation https://postgrest.org/
+
+PostgREST docs use the reStructuredText format, check this [cheatsheet](https://github.com/ralsina/rst-cheatsheet/blob/master/rst-cheatsheet.rst) to get acquainted with it.
+
+To build the docs locally, use [nix](https://nixos.org/nix/):
+
+```bash
+  nix-shell
+```
+
+Once in the nix-shell you have the following commands available:
+
+- `postgrest-docs-build`: Build the docs.
+- `postgrest-docs-serve`: Build the docs and start a livereload server on `http://localhost:5500`.
+- `postgrest-docs-spellcheck`: Run aspell.
+
+## Documentation structure
+
+This documentation is structured according to tutorials-howtos-topics-references. For more details on the rationale of this structure, 
+see https://www.divio.com/blog/documentation.