add comprehensive documentation (#9537)

docs/misc/alpine-install.func/ALPINE_INSTALL_FUNC_FLOWCHART.md

@@ -0,0 +1,29 @@
+# alpine-install.func Flowchart
+
+Alpine container initialization flow (apk-based, OpenRC init system).
+
+## Alpine Container Setup Flow
+
+```
+Alpine Container Started
+    ↓
+setting_up_container()
+    ↓
+verb_ip6()              [optional - IPv6]
+    ↓
+update_os()             [apk update/upgrade]
+    ↓
+network_check()
+    ↓
+Application Installation
+    ↓
+motd_ssh()
+    ↓
+customize()
+    ↓
+cleanup_lxc()
+    ↓
+Complete ✓
+```
+
+**Last Updated**: December 2025