case-sensitive paths on a case-insensitive filesystem

```
$ git clone git@github.com:mosip/documentation.git
...
warning: the following paths have collided (e.g. case-sensitive paths
on a case-insensitive filesystem) and only one from the same
colliding group is in the working tree:

  'docs/.gitbook/assets/feature Health.png'
  'docs/.gitbook/assets/feature health.png'
```