add template-configs, script to launch network

This is the set of scripts I've written for myself over the years to easily
configure and run Osmocom core networks on my lab computer. I hope this will be
useful to others as well.
diff --git a/net/config_2g3g b/net/config_2g3g
new file mode 100644
index 0000000..8e11614
--- /dev/null
+++ b/net/config_2g3g
@@ -0,0 +1,50 @@
+ETH_DEV=eth0
+APN_DEV=apn0
+
+PUBLIC_IP="192.168.0.23"
+PUBLIC_IP2="192.168.0.42"
+
+MCC=001
+MNC=01
+
+HLR_IP="127.0.0.1"
+
+MSC_PC="0.23.1"
+
+SGSN_IP="${PUBLIC_IP}"
+SGSN_PC="0.23.2"
+SGSN_GB_PORT=23000
+
+GBPROXY_IP="${PUBLIC_IP}"
+GBPROXY_GB_PORT=7777
+
+PCU_GB_PORT=23000
+
+MGW4MSC_IP="${PUBLIC_IP}"
+MGW4MSC_VTY_IP="127.0.0.1"
+
+BSC_IP="${PUBLIC_IP}"
+BSC_PC="0.42.0"
+MGW4BSC_IP="${PUBLIC_IP2}"
+MGW4BSC_PORT="12427"
+MGW4BSC_VTY_IP="127.0.0.2"
+
+HNBGW_PC="0.3.0"
+HNBGW_IP="${PUBLIC_IP}"
+
+GGSN_IP="${PUBLIC_IP2}"
+GGSN_DNS0="192.168.0.1"
+GGSN_DNS1="9.9.9.9"
+GGSN_NET="192.168.42.0/24"
+
+HNODEB_IP="192.168.0.124"
+UARFCN=4357
+SCRAMBLE=157
+LAC=1${UARFCN}
+RAC=11
+
+HNODEB_IP2="192.168.0.23"
+UARFCN2=4358
+SCRAMBLE2=258
+LAC2=2${UARFCN2}
+RAC2=22