Add Docker support and configuration for SRS SIP

- Created a new README_cross.md file with Docker build instructions.
- Updated srs.conf to include logging configuration options.
- Added docker-compose.yml to define the SRS SIP service with necessary ports and volume mappings.
- Introduced config.yaml for general and GB28181-specific configurations.
- Added initial srs.conf with settings for RTMP, HTTP API, and WebRTC support.

run/conf/config.yaml

@@ -0,0 +1,20 @@
+# 通用配置
+common:
+  # [debug, info, warn, error]
+  log-level: "info"
+  log-file: "logs/srs-sip.log"
+
+# GB28181配置
+gb28181:
+  serial: "34020000002000000001"
+  realm: "3402000000"
+  host: "0.0.0.0"
+  port: 5060
+  auth:
+    enable: false
+    password: "123456"
+
+# HTTP服务配置
+http:
+  listen: 8025
+  dir: ./html