Move mongoose docs to https://cesanta.com/docs/

PUBLISHED_FROM=ebf5568abe82952ab2751298185a10189098013f

docs/overview/conn-flags.md

@@ -1,6 +1,4 @@
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-title: Connection flags
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+# Connection flags
 
 Each connection has a `flags` bit field. Some flags are set by Mongoose, for
 example if a user creates an outbound UDP connection using a `udp://1.2.3.4:5678`