add new helpers

[pmoroney]

I have added quite a few helpers that I have used for documentation and client library generation.

goZeroValue: returns the Go zero value for a field.

leadingComment, trailingComment, leadingDetachedComments: returns the comments in the protobuf file near the item.

stringFieldExtension, boolFieldExtension: returns either a string or a bool field extension in the protobuf file when given the extension id.

isFieldMap, fieldMapKeyType, fieldMapValueType: functions to figure out if a field is a map and what types are the keys and values.

replaceDict: does a replace for every string in a sprig dictionary.

[weitzj]

Thank you so much. I am really looking forward to this

[weitzj]

Love it!

i.e. (working example): "add a multiline Golang code-comment in front of my Service:

//{{regexSplit "\n" (trimSuffix "\n" (.service | leadingComment)) -1 | join "\n//"}}

Idea:

• remove any trailing newlines
• split at newlines and join with \n//