birdc: initial creation (#9929)

Signed-off-by: Marek Küthe <m.k@mk16.de>

pages/common/birdc.md

@@ -0,0 +1,37 @@
+# birdc
+
+> Bird remote control.
+> Command tool to retrieve information like routes from bird and perform configurations during runtime.
+> More information: <https://bird.network.cz/>.
+
+- Open the remote control console::
+
+`birdc`
+
+- Reload the configuration without restarting Bird:
+
+`birdc configure`
+
+- Show the current status of Bird:
+
+`birdc show status`
+
+- Show all active protocols:
+
+`birdc show protocols`
+
+- Show all details about a protocol:
+
+`birdc show protocols {{upstream1}} all`
+
+- Show all routes that contain a specific AS number:
+
+`birdc "show route where bgp_path ~ [{{4242120045}}]"`
+
+- Show all best routes:
+
+`birdc show route primary`
+
+- Show all details of all routes from a given prefix:
+
+`birdc show route for {{fd00:/8}} all`