feat: add svelte and astro filetype (#398)

Author: jcha0713

data/plenary/filetypes/builtin.lua

@@ -20,32 +20,34 @@ end
 return {
   extension = {
     ['_coffee'] = 'coffee',
-    ['coffee'] = 'coffee',
+    ['astro'] = 'astro',
     ['cljd'] = 'clojure',
+    ['coffee'] = 'coffee',
     ['dart'] = 'dart',
+    ['erb'] = 'eruby',
     ['ex'] = 'elixir',
     ['exs'] = 'elixir',
-    ['erb'] = 'eruby',
-    ['tres'] = 'gdresource',
-    ['tscn'] = 'gdresource',
-    ['gd'] = 'gdscript',
     ['fnl'] = 'fennel',
+    ['gd'] = 'gdscript',
     ['gql'] = 'graphql',
-    ['graphql'] = 'graphql',
     ['gradle'] = 'groovy',
+    ['graphql'] = 'graphql',
     ['hbs'] = 'handlebars',
     ['hdbs'] = 'handlebars',
     ['janet'] = 'janet',
-    ['jsx'] = 'javascriptreact',
     ['jl'] = 'julia',
+    ['jsx'] = 'javascriptreact',
     ['kt'] = 'kotlin',
     ['nix'] = 'nix',
+    ['plist'] = 'xml',
     ['purs'] = 'purescript',
-    ['rkt'] = 'racket',
     ['res'] = 'rescript',
     ['resi'] = 'rescript',
+    ['rkt'] = 'racket',
+    ['svelte'] = 'svelte',
+    ['tres'] = 'gdresource',
+    ['tscn'] = 'gdresource',
     ['tsx'] = 'typescriptreact',
-    ['plist'] = 'xml',
   },
   file_name = {
     ['cakefile'] = 'coffee',