Fix navigate option in git config example
The navigate option does not work when present in the `[core]` section of the git config because it is not a git option. It works correctly when present in the `[delta]` section.
```gitconfig
[core]
pager = delta
- navigate = true
[interactive]
diffFilter = delta --color-only
[diff]
colorMoved = true
+
+[delta]
+ navigate = true
```
## A syntax-highlighting pager for git, diff, and grep output
