Add JS++ search engine in Firefox

firefox-jspp-search-engine.js

//i This code adds a custom search engine in Firefox that utilizes Google and
//i restricts the scope of the search to the JS++ documentation.
//i
//i Tested with Firefox Developer Edition v64.
//i
//i For more information about the language, see: https://www.onux.com/jspp/
//i
//i How to run:
//i - Open the browser settings and go to "One-click Search Engines."
//i - From the hamburger menu on the browser toolbar,
//i   choose "Developer" > "Toggle Tools."
//i - In the developer tools, click the "Console" tab.
//i - Paste this code and hit enter.
//i - A new search engine should have appeared on the settings page.
//i - For troubleshooting, look here whether I missed to mention something
//i   necessary: https://www.reddit.com/r/firefox/comments/7fr039/how_to_add_custom_search_engines/dqelr3g/
//i
//i The search engine can be removed by means of the user interface.

Services.search.addEngineWithDetails(
    /*name:*/        "JS++ Docs",
    /*iconURL:*/     "https://www.onux.com/jspp/favicon.ico",
    /*alias:*/       "jspp",
    /*description:*/ "Google search on docs.onux.com",
    /*method:*/      "GET",
    /*url:*/         "https://www.google.com/search?q={searchTerms}+++++site%3Adocs.onux.com"

    //i In contrast to what is documented on an unofficial page[1], the
    //i `sitesearch` URL parameter shows up in the search page's text box as a
    //i `site:...` constaint (Dec. 2018). So, we include the constraint in the
    //i query and set it apart from the search terms.
    //i
    //i [1] https://github.com/NikolaiT/GoogleScraper/blob/master/GoogleScraper/search_engine_parameters.py
);