Try fix footnotes

Author: andersfugmann

README.md

@@ -31,14 +31,14 @@ The main features include:
 | proto2 groups     | Not supported[^2]   | Ignored       | ?                   |
 | json mappings     | Supported           | Supported     | ?                   |
 
-[^1] Ocaml-bp has a sister project `Ocaml-bp-plugin` which emit
+[^1]: Ocaml-bp has a sister project `Ocaml-bp-plugin` which emit
 Ocaml-pb definitions from a `.proto`. The plugin parses files are proto2
 Ocaml type definitions (all fields are option types), and repeated
 fields are not packed by default.
 
-[^2] Groups has been deprecated by google and should not be used.
+[^2]: Groups has been deprecated by google and should not be used.
 
-[^3] `ocaml_protoc` will always transmit all fields that are not
+[^3]: `ocaml_protoc` will always transmit all fields that are not
 marked optional, and does not *strictly* comply to the protobuf
 specification.
 
@@ -121,13 +121,7 @@ can generate the Ocaml code by running
 
 Parameters are separated by `;`
 
-[^6] When using this option, all dependencies needs to be compiled
-using this option as well. E.g. if the protobuf file dependes on
-*google well known types*, you will need to rebuild using
-`prefix_output_with_package=true` as
-well. This dune file
-[dune](https://github.com/andersfugmann/ocaml-protoc-plugin/blob/main/test/test_params/google_types_prefixed/dune)
-lists how to do that.
+[^6]: When using this option, all dependencies needs to be compiled using this option as well. E.g. if the protobuf file dependes on *google well known types*, you will need to rebuild using `prefix_output_with_package=true` as well. This dune file [dune](https://github.com/andersfugmann/ocaml-protoc-plugin/blob/main/test/test_params/google_types_prefixed/dune) lists how to do that.
 
 If `protoc-gen-ocaml` is not located in the path, it is possible to
 specify the exact path to the plugin: