chore: mention mise and aqua in the readme (#409)

Please, consider mentioning `mise` and `aqua` in the readme.

Reference: `jsonschema` was recently added to the `aqua`
(aquaproj/aqua-registry#39066) and `mise`
(jdx/mise#5714) registries.

Thanks for this project! I was looking for a tool like this one for some
time.

Signed-off-by: mrazauskas <tom@mrazauskas.de>

Author: mrazauskas

README.markdown

@@ -132,7 +132,7 @@ Where `X.Y.Z` is replaced with the desired version. For example:
 - run: jsonschema fmt path/to/schemas --check
 ```
 
-### From NPM
+### From npm
 
 ```sh
 npm install --global @sourcemeta/jsonschema
@@ -144,6 +144,12 @@ npm install --global @sourcemeta/jsonschema
 pip install sourcemeta-jsonschema
 ```
 
+### From mise
+
+```sh
+mise use jsonschema
+```
+
 ### From GitHub Releases
 
 We publish precompiled binaries for every supported platform to [GitHub