croc: add page (#3917)

pages/common/croc.md

@@ -0,0 +1,32 @@
+# croc
+
+> Send and receive files easily and securely over any network.
+> More information: <https://github.com/schollz/croc>.
+
+- Send a file or folder:
+
+`croc send {{path/to/file}}`
+
+- Send a file or folder with a specific passphrase:
+
+`croc send --code {{passphrase}} {{path/to/file}}`
+
+- Receive a file or folder on receiving machine:
+
+`croc {{passphrase}}`
+
+- Send and connect over a custom relay:
+
+`croc --relay {{ip_to_relay}} send {{path/to/file}}`
+
+- Receive and connect over a custom relay:
+
+`croc --relay {{ip_to_relay}} {{passphrase}}`
+
+- Host a croc relay on the default ports:
+
+`croc relay`
+
+- Display paramenters and options for a croc command:
+
+`croc {{send|relay}} --help`