* Handle words containing bare '#'
Only a word beginning with a '#' starts a comment. A word can contain
'#' character without escaping as long as it is not the first character.
See: Bash Reference Manual section '3.1.3 Comments'
https://www.gnu.org/software/bash/manual/bash.html#Comments
* Regenerate
* Rename prebuild target clashing with build target
* Add test:watch target and documentation
* Support multiple statements in substitutions
* Inline the _statements rule
This removes a reduction step by the `_statements -> _statement` rule,
which avoids a reduce/reduce conflict between `_statements` and
`command`.