feat: plugin code and updates

plugin/shellspec.vim

@@ -0,0 +1,29 @@
+" ShellSpec DSL plugin
+" Neovim language support for ShellSpec testing framework
+" Repository: https://github.com/ivuorinen/nvim-shellspec
+" Author: Ismo Vuorinen
+
+if exists('g:loaded_shellspec')
+  finish
+endif
+let g:loaded_shellspec = 1
+
+" Commands
+command! ShellSpecFormat call shellspec#format_buffer()
+command! -range ShellSpecFormatRange call shellspec#format_selection()
+
+" Auto commands
+augroup ShellSpec
+  autocmd!
+  autocmd FileType shellspec setlocal commentstring=#\ %s
+  autocmd FileType shellspec setlocal foldmethod=indent
+  autocmd FileType shellspec setlocal shiftwidth=2 tabstop=2 expandtab
+augroup END
+
+" Optional: Auto-format on save
+if get(g:, 'shellspec_auto_format', 0)
+  augroup ShellSpecAutoFormat
+    autocmd!
+    autocmd BufWritePre *.spec.sh,*_spec.sh ShellSpecFormat
+  augroup END
+endif