Build, test, and debug regular expressions
Matches any substring that starts with a digit, followed by any run of characters (`.{0,}` is equivalent to `.*`), then a literal dot, and optionally more digits, capturing the whole match in group 1. Intended for selecting decimal numbers like 3.14 or 5., but because the middle part matches any character, it greedily spans letters or symbols between the leading digit and the dot (e.g. '1abc.2'). Useful for loosely extracting dotted numeric values from text with the global flag.