Fixed several typos in comments and documentation

[kpumuk]

While reading the source of the project, I found a few typos here and there.

[ttilberg]

Please additionally add:

--- a/README.md
+++ b/README.md
@@ -78,7 +78,7 @@ Only one service at a time can route a specific host:
     kamal-proxy deploy service1 --target web-1:3000 --host app1.example.com
     kamal-proxy deploy service2 --target web-2:3000 --host app1.example.com # returns "Error: host is used by another service"
     kamal-proxy remove service1
-    kamal-proxy deploy service2 --target web-2:3000 --host app1.example.com # suceeds
+    kamal-proxy deploy service2 --target web-2:3000 --host app1.example.com # succeeds

[kevinmcconnell]

Nice, thanks @kpumuk & @ttilberg!