Compiler configuration in a CSON options file

Feature request:

Add a compiler configuration file, perhaps `coffeeconfig.cson`. Instead of placing CLI options in `package.json`, this would permit running the CLI commands with a consistent per-project configuration.

### Input Code

Possible defaults for `coffeeconfig.cson`, added transpilation because that's the default suggestion in the documentation:

```coffee
compile: true
map: false
inlineMap: false
output: "out"
watch: false
bare: true
header: false
literate: false
cli:
print: false
stdio: false
ast: false
tokens: false
nodes: false
transpile:
presets: ['@babel/env']
```

### Context

I'm trying to support project configuration for a future VSCode CoffeeScript IDE equal to Atom but with special CSON treatment. Unfortunately, my users won't be able to configure the compiler if they use my extension ATM.

The issue names no files, tests, or entry points. Start by locating how the CLI currently reads package.json options, then determine how a per-project coffeeconfig.cson file should interact with those options. Done means the compiler and CLI consistently honor the proposed configuration format, with behavior covered by tests and documented for users.

Written by the indexing model from the issue text.