Add linkbot and config example for linkbot

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

config.example.toml

@@ -34,4 +34,28 @@ channels = ["#fortune_telling"]
 # documentation for the values you can set.
 
 # A list of fortunes, or a path to a list of fortunes - one per line.
-fortunes = "data/fortunes.txt"
+fortunes = "data/fortunes.txt"
+
+[[plugins]]
+# Linkbot module will fetch the title of a value at a URL.
+module = "plugins.linkbot"
+
+# Whether URLs that are pointing to private IP addresses are allowed.
+# This is recommended to be left false.
+# default: false
+# allow_private = false
+
+# Additional blocked hosts, URLs, and IP ranges.
+# You don't need to block things like localhost, 192.168.0.0/16, etc if you are
+# using `allow_private = false` above
+# default: []
+blocked = [
+    # This can take the form of a URL,
+    "https://www.example.com/full-page/",
+    # a hostname,
+    "www.example.com",
+    # an IP address,
+    "8.8.8.8",
+    # or an IP subnet
+    "8.8.0.0/16"
+]