Don't report lint errors in boilerplate code

Fixes #37

Old-style configs were broken

Fixed #35

Update to Peggy 4.0.1

Update dependencies

Update to Peggy 4.0.0

• Updated to Peggy4, including support for importing rules from external libraries
• Added valid-imports rule

Minor bug fixes

• Take the indentation of code blocks from the first non-blank line of code in the block. Once we have an indent rule, we can be much more opinionated than this, but too many of the example grammars have hard-to-predict block indentation at the moment.
• Make sure that when looking for return in semantic action bodies, it is at least a whole, single word. The current approach is not good, since we're not parsing the JS inside the block to ensure that the word "return" isn't in a comment or something, but it's better than nothing to catch a common mistake.

First release

First set of rules.

Please suggest more rules, or other potential configurations for the existing rules.