fix: the `renderer#ParseTemplates()` does not work properly
fix: the `renderer#ParseTemplates()` does not work properly

e.g. r.air.Config.TemplateRoot == ""

./
  index.html

./parts/
  header.html
  footer.html

will be parsed into:

"ndex.html", "arts/header.html", "arts/footer.html".

The first character accidentally disappeared.

sheng/air