fix: allow variables to start with numbers

[guilhas07]

Problem:

Variables in go templates can start with numbers.

https://pkg.go.dev/text/template

A variable name, which is a (possibly empty) alphanumeric string preceded by a dollar sign, 
such as $piOver2 or $ The result is the value of the variable. Variables are described below.

Example in go tests:

https://github.com/golang/go/blob/44a6f817ea0fbeb3ba4aa398794c4e80dba13b1e/src/text/template/parse/lex_test.go#L223

Solution:

Create a new token for variable identifiers.

[qvalentin]

Looks good, please also run npm run build to generate the helm dialect.