Make flags additive and clean up docs

This means that you have to turn on features now instead of disabling
them like auth and https.

In addition:
- Allow multiple options for auth (only password for now).
- Combine the install docs since they had many commonalities and
- generally simplified them (hopefully not too much).
- Move all example configs into docs/examples.

doc/examples/fail2ban.conf

@@ -0,0 +1,15 @@
+# Fail2Ban filter for code-server
+
+[Definition]
+
+failregex = ^INFO\s+Failed login attempt\s+{\"password\":\"(\\.|[^"])*\",\"remoteAddress\":\"<HOST>\"
+
+# Use this instead for proxies (ensure the proxy is configured to send the
+# X-Forwarded-For header).
+# failregex = ^INFO\s+Failed login attempt\s+{\"password\":\"(\\.|[^"])*\",\"xForwardedFor\":\"<HOST>\"
+
+ignoreregex =
+
+datepattern = "timestamp":{EPOCH}}$
+
+# Author: Dean Sheather