fix: read config file before defaulting script parameter

[lennym]

If I have a nodemon.json config file with an exec property, then this is automatically appended with index.js when running nodemon standalone.

I would expect this to be equivalent to running nodemon --exec "my cmd" - that is providing an exec prevents defaulting of script to index.js.

To resolve, move the code which defaults the script property when exec is undefined to after the config files have been read, so that the behaviour is the same irrespective of whether properties are set in CLI flags or in nodemon.json.

[lennym]

As an unrelated aside, I wrote a first version of the commit message for 8a4dc77 and tried to commit before I realised that you have commitlint enabled, which then discarded my lovingly crafted message because I didn't have fix: as the first line.

I've no problem with commitlint as a concept, but it'd be good to get some warning as a contributor before it discards my messages.

Where am I going with this..?

I wrote a module in response to this slight that allows for custom per-project commit templates - https://www.npmjs.com/package/commit-template. I might suggest its use for output something like:

# Warning: this project uses commitlint. Your message must be in the following form or it will not be accepted:
# <example message>