Do not source orphaned sh files

[windowsrefund]

I have the tinty_source_shell_theme function defined in my environment which runs each time I start a shell.

After noticing some oddness with my shell colors, I decided to poke around in the directory used to store the .sh files which are sourced by the function above. That's when I noticed an orphan:

> ls -go .local/share/tinted-theming/tinty/*.sh
-rw-rw-r-- 1 5102 Sep 15 18:00 .local/share/tinted-theming/tinty/base16-shell-scripts-file.sh
-rw-rw-r-- 1  428 Sep 24 23:14 .local/share/tinted-theming/tinty/tinted-fzf-sh-file.sh
-rw-rw-r-- 1 5109 Sep 24 23:14 .local/share/tinted-theming/tinty/tinted-shell-scripts-file.sh

I'm thinking I mucked something up along the way as I've been tweaking config. Regardless of how it happened, that base16-shell-scripts-file.sh script is an obvious orphan which should no longer be sourced. Here's what I'm doing to overcome the issue.

[windowsrefund]

ah ha, the orphaed file was created as a result of 2141665

[JamyGolden]

Thanks for the PR. This is related to #33. Once that feature exists, we could run a tinty clean before the tinty init and it should clean things up, however this is still a valuable change.

I've added suggested edits to change shell back to sh because sh gives the markdown code block syntax highlighting, as far as I can see shell isn't supported at all: https://github.com/github-linguist/linguist/blob/main/lib/linguist/languages.yml#L282 which gets mapped to https://github.com/ajaxorg/ace/blob/master/src/mode/sh.js