Allow using directory bind mounts for a docker container

This helps with a situation when some applications do not allow mounting
individual files, but whole directories. In that case users could mount
`/config` directory with a single file, `config.toml`: `-v
/path/to/dir:/config`. Also, there is a backward compatibility to using
a single `/config.toml`

Add more architectures for mtg

Document a necessety of increasing limits for systemd unit

Add PGO

It seems that default DynamicUser limits are very low. We have to
increase them anyway.

Avoid double buffering in TLS hot path

Optimize waiting time for TLS chunker

Show ip of telegram endpoints in event stream

Fix flaky test

fix: ensure network.Dial and MakeHTTPClient use socks5 proxy

The package `network/v2/proxy_network.go` does not wrap `network.Dial`
and `network.MakeHTTPClient`, which causes them to bypass the SOCKS5
proxy and initiate TCP connections directly from the local machine.

Fix preferIPOnlyIPv6

Add document about best practices

Decrease relay buffer size