Highlight ICU MessageFormat

Add highlights to ICU MessageFormat text to make it easier for translators to read and clearer what text needs to be translated.

International Components for Unicode (ICU) is an open source project of mature C/C++ and Java libraries for Unicode support, software internationalization, and software globalization. The ICU MessageFormat class uses message "pattern" strings with variable-element placeholders (called "arguments" in the API docs) enclosed in {curly braces}. The argument syntax can include formatting details, otherwise a default format is used. For details about the pattern syntax and the formatting behavior see the MessageFormat API docs (Java, C++, C). ICU is very powerful for internationalizing your app or website. However, a lot of Translation Management Systems (TMS) do not support ICU MessageFormat. This means their interfaces do not highlight what part of text a translator should translate, and which parts are "code". This Chrome extension is intended for translators working in a TMS that does not support ICU MessageFormat highlighting. It will find ICU MessageFormat on a web page and add highlighting to it to make it more obvious which parts of the text should be translated and which should be left alone. References: - https://en.wikipedia.org/wiki/International_Components_for_Unicode - http://userguide.icu-project.org/intro - http://userguide.icu-project.org/formatparse/messages - format-message.github.io/icu-message-format-for-translators/editor.html