Added Perl LSP support with PLS

You'll need to have your Cpan package bin directory in your $PATH and
then you'll need to install the following modules with Cpan or cpanm:
  - PPI: https://metacpan.org/pod/PPI
  - PLS: https://metacpan.org/pod/PLS

See my post to the vim-lsp wiki for more info on how to set it up:
  https://github.com/prabirshrestha/vim-lsp/wiki/Servers-Perl

.vimrc

@@ -60,6 +60,15 @@ if executable('pylsp')
         \ })
 endif
 
+" Perl
+if executable('pls')
+    au User lsp_setup call lsp#register_server({
+        \ 'name': 'pls',
+        \ 'cmd': {server_info->['pls']},
+        \ 'allowlist': ['perl'],
+        \ })
+endif
+
 " Bash
 if executable('bash-language-server')
     au User lsp_setup call lsp#register_server({