Because pt_PT and pt_BR have many differences, such as how
the word “file” gets translated, Guix’ pt_BR info manual is
called (guix.pt_BR) instead of (guix.pt).
* gnu/system/install.scm (log-to-info): Try region coded manual
file names.
(%installation-node-names): Add node names for pt_BR and zh_CN.
Change-Id: I89beebd323ee69ca83c22321c9d9e664b32cf6f3