chore: resolve byte-compile-file warnings

[jtbx]

catppuccin-theme.el:131:6: Warning: ‘beginning-of-buffer’ is for interactive
    use only; use ‘(goto-char (point-min))’ instead.
catppuccin-theme.el:144:16: Warning: reference to free variable
    ‘catppuccin-flavor-alist’

In catppuccin-reload:
catppuccin-theme.el:192:2: Warning: docstring wider than 80 characters

In catppuccin-load-flavor:
catppuccin-theme.el:198:2: Warning: docstring wider than 80 characters catppuccin-theme.el:198:2: Warning: docstring has wrong usage of unescaped
    single quotes (use \= or different quoting)