@Nonnull
	public static RegexRule addLanguage(@Nonnull String path) throws IOException {
		InputStream stream = RegexLanguages.class.getResourceAsStream(path);
		if (stream == null)
			stream = new FileInputStream(path);
		String name = cutOffAtFirst(shortenPath(path), ".");
		return addLanguage(name, stream);
	}
Adds support for the language outlined by the contents of the given file.
File path should point to a json file modeling {@link RegexRule}.

@param path
		Path to regex json file. The language name is the file name, without the extension.
		<ul>
		    <li>Internal paths start with {@code /}.</li>
		    <li>External paths should exist if checked by {@code new File(path).exists()}.</li>
		</ul>

@return Language root rule.

@throws IOException
		When the file cannot be read or mapped into the rule structure.
recaf-ui/src/main/java/software/coley/recaf/ui/control/richtext/syntax/RegexLanguages.java