patch 9.1.1134: filetype: Guile init file not recognized

patch 9.1.1134: filetype: Guile init file not recognized

Problem:  filetype: Guile init file not recognized
Solution: detect '.guile' file as scheme filetype
          (David Mandelberg)

References:

https://www.gnu.org/software/guile/manual/html_node/Init-File.html
> When run interactively, Guile will load a local initialization file
> from ~/.guile. This file should contain Scheme expressions for
> evaluation.

closes: #16683

Signed-off-by: David Mandelberg <david@mandelberg.org>
Signed-off-by: Christian Brabandt <cb@256bit.org>