Idea: Add filters for altering resolved values

[DavidWells]

It might be cool to support filters on values.

Example:

key: ${file(fetchSecrets.js).value | toUpper}

key: ${file(fetchSecrets.js).value | toTitle}

key: ${file(fetchSecrets.js).value | join ","}

etc.

[DavidWells]

Implemented!