Introduce doc/examples/ directory

It contains simple usual setups to get started with osmo-gsm-tester,
such as creating a 4G network using srsLTE or a 2G network using the
osmocom stack (+ ofono modems).

Change-Id: I55d5b1152da201799af21a77ef6c562f97bd94fc
diff --git a/doc/examples/4g_srsLTE/scenarios/mod-enb-meas-event@.conf b/doc/examples/4g_srsLTE/scenarios/mod-enb-meas-event@.conf
new file mode 100644
index 0000000..44f4fcd
--- /dev/null
+++ b/doc/examples/4g_srsLTE/scenarios/mod-enb-meas-event@.conf
@@ -0,0 +1,7 @@
+modifiers:
+  enb:
+  - enable_measurements: true
+    ${param1}_report_type: ${param2}
+    ${param1}_report_value: ${param3}
+    ${param1}_hysteresis: ${param4}
+    ${param1}_time_to_trigger: ${param5}