Content type with parameters does not work for prefilling the request example in ApiDemoPanel

Describe the bug

We are using parameters for content types and it seems that the Body component in the theme does not have a valid condition for it.
https://github.com/PaloAltoNetworks/docusaurus-openapi-docs/blob/main/packages/docusaurus-theme-openapi-docs/src/theme/ApiDemoPanel/Body/index.tsx

Example of Swagger path with content type that includes parameters such as charset:

  /store/order:
    post:
      tags:
        - store
      summary: Place an order for a pet
      description: ""
      operationId: placeOrder
      responses:
        "200":
          description: successful operation
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Order"
            application/xml:
              schema:
                $ref: "#/components/schemas/Order"
        "400":
          description: Invalid Order
          content:
            application/json:
              example:
                status: 400
                message: "Invalid Order"
      requestBody:
        content:
          application/json; charset=utf-8:
            schema:
              $ref: "#/components/schemas/Order"

See requestBody > content > application/json; charset=utf-8:

Expected behavior

The request body example is pre-filled from the OpenAPI documentation even when specified parameters for Content Body. (application/json; charset=utf-8:)

Current behavior

There is nothing pre-filled (application/json; charset=utf-8:).

Possible solution

I'm not sure, but I can guess that all conditions in the Body component should probably not have an equal sign, but a condition on whether it contains a string.

From:

if (contentType === "application/json" || contentType.endsWith("+json"))

To something like:

if (contentType.includes("application/json") || contentType.endsWith("+json"))

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/includes

Steps to reproduce

1. Clone https://github.com/PaloAltoNetworks/docusaurus-openapi-docs
2. Change this line in petstore.yaml to application/json; charset=utf-8:
3. Regenerate API doc (yarn clean-api && yarn gen-api)
4. Start the demo (yarn watch:demo)
5. Open http://localhost:3000/petstore_versioned/place-order and see that the demo request example is empty

Context

It seems that parameters are also valid according to MDN and OpenAPI specifications.

• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type
• https://swagger.io/specification/#media-types

Your Environment

• Version used: Current main commit https://github.com/PaloAltoNetworks/docusaurus-openapi-docs/commit/28ec9357b7b50ea4cb060b2e7f9ab3d5118adad6 and v2.0.0-beta.3
• Environment name and version (e.g. Chrome 59, node.js 5.4, python 3.7.3): Brave Version 1.52.129 Chromium: 114.0.5735.198 (Official Build) (arm64); node v18.16.1, yarn 1.22.19
• Operating System and version (desktop or mobile): desktop MacOS Sonoma 14.0 Beta
• Link to your project: none

Start in packages/docusaurus-theme-openapi-docs/src/theme/ApiDemoPanel/Body/index.tsx and reproduce the issue by changing the content type in demo/examples/petstore.yaml, then running yarn clean-api && yarn gen-api and yarn watch:demo. Done means the request body example is pre-filled for application/json; charset=utf-8, as it is for application/json.