nvim: Add efm languageserver

Added a general purpose languageserver to round out the language server
possibilities. For now only configured to take care of bash linting
(using shellcheck) and formatting, but can be extended to a variety of
other languages (even helping more prosaic forms like markdown and pandoc).

bootstrap/packages.txt

@@ -34,6 +34,7 @@ docx2txt
 duf
 dunst
 dust
+efm-langserver
 entr
 evince
 exa
@@ -214,6 +215,7 @@ vagrant
 vi
 vifm
 vim-language-server
+vimiv
 visidata
 xcape
 xclip

nvim/.config/nvim/lua/plug/_lsp.lua

@@ -111,6 +111,32 @@ end
 -- set up simple servers
 for _, lsp in ipairs(servers) do lspcfg[lsp].setup {on_attach = on_attach} end
 
+lspcfg.efm.setup {
+    on_attach = on_attach,
+    init_options = {
+        documentFormatting = true,
+        codeAction = true,
+        completion = true,
+        documentSymbol = true,
+        hover = true
+    },
+    filetypes = {"sh"},
+    settings = {
+        rootMarkers = {".git/"},
+        languages = {
+            sh = {
+                {
+                    lintCommand = 'shellcheck -f gcc -x',
+                    lintFormats = {
+                        '%f:%l:%c: %trror: %m', '%f:%l:%c: %tarning: %m',
+                        '%f:%l:%c: %tote: %m'
+                    }
+                }, {formatCommand = 'shfmt -ci -s -bn', formatStdin = true}
+            }
+        }
+    }
+}
+
 -- requires the lua-language-server package to be installed
 -- The arch package defaults to the following directory
 local sumneko_root_path = "/usr/share/lua-language-server"