Fix too eager templater reg exp

[FredericRuaudel]

This pull request is fixing a simple bug that prevent the option to have two or more patterns without any spaces between them without having to add spaces inside the curly braces:

examples of pattern this PR solves:

"${num}/${total}"
"${value}${index}"
"${filename}.${ext}"
...

In the current code, it doesn't works because the genericPlaceholderPattern is too eager and split the patterns as one element (eg: ["${num}/${total}"] instead of ["${num}", "/", "${total}"]) then it changes the first value so we get only the equivalent of ${num} if we keep my last example.

And indeed, they all can be solved like this:

"${ num }/${ total }"
"${ value }${ index }"
"${ filename }.${ ext }"
...

but let's not limiting the options of your users ? 😉

thanks in advance!

[codecov]

Codecov Report

Merging #118 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master     #118   +/-   ##
=======================================
  Coverage   95.58%   95.58%           
=======================================
  Files           6        6           
  Lines         249      249           
  Branches       75       75           
=======================================
  Hits          238      238           
  Misses         10       10           
  Partials        1        1

Impacted Files	Coverage Δ
src/utils.js	100% <100%> (ø)	⬆️

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[ryandrewjohnson]

@FredericRuaudel Good catch! Thanks for the contribution 🎉