LSP working for PHP

backend/src/langs.ts

@@ -717,6 +717,7 @@ end.
     repl: "php -a",
     main: "main.php",
     run: "php -d auto_prepend_file=main.php -a",
+    lsp: "intelephense --stdio",
     template: `<?php
 
 echo "Hello, world!\\n";

scripts/docker-install-phase4.bash

@@ -52,6 +52,9 @@ julia -e 'using Pkg; Pkg.add("LanguageServer")'
 # Perl
 cpanm -n Devel::REPL
 
+# PHP
+npm install -g intelephense
+
 # ReasonML
 npm install -g bs-platform