Tokens plugin MVP

[floscr]

Need to add this to the tokens plugin runtime (I've just edited the file in node_modules)
frontend/node_modules/@penpot/plugins-runtime/index.js

      getTokens() {
        return e("content:read"), t.context.getTokens();
      },
      setTokens(tokens) {
        return e("content:write"), t.context.setTokens(tokens);
      },

Here's the plugin that uses the API:
https://github.com/tokens-studio/penpot-github-sync-mvp/