Out of Number (e.g. 2/8)

### 📋 Description

I'm sure this can be implemented for other cases, But for me, it would be like this; badge/shield that uses 2 figures, issues opened and closed. Also an option for custom text.

My ideal case would be to have this; "X/Y Completed"
Where X is the number of open issues with a particular label, and Y being the closed issues matching the same label for X.
e.g. _(3/5 Complete)_

### 🔗 Data

GitHub, no auth

### 🎤 Motivation

It could be useful in many cases, it will also mean the start of a new system of bespoke badges in the future too

Start by reviewing the issue's proposed GitHub data source and the desired “X/Y Completed” output. Define what the badge should count for a matching label, how custom text is supplied, and how the feature fits a future bespoke-badge system; done means the requested badge behavior and scope are specified clearly enough to implement.

Written by the indexing model from the issue text.