add more instructions on how to install the jdtls lsp client

after/ftplugin/java.lua

@@ -4,7 +4,18 @@ if not status_ok then
 end
 
 jdtls.start_or_attach {
-  cmd = {'/home/squibid/Downloads/jdt-lang-serv/bin/jdtls'},
+  --[[
+    There are 3 ways to get the jdtls server (ranked from easiest to hardest):
+    1. Install it from your distros repo
+    2. Download a milestone from: https://download.eclipse.org/jdtls/milestones
+       then extract it.
+    3. Compile it from source: https://github.com/eclipse/eclipse.jdt.ls
+       good luck :)
+
+    For all 3 of these you need to put the path to the jdtls binary in the
+    "cmd" section below
+  ]]
+  cmd = {''},
   root_dir = vim.fs.dirname(
     vim.fs.find({ 'gradlew', '.git', 'mvnw' }, { upward = true })[1]
   ),