* Expanded explanation, added links
The earlier version of this did not expand fully on usage patterns or how SSH operates. I added an explanation of why you don't need to specify the username, additional examples, and links for further investigation.
* Update index.md
* some article refresh
this had some misinformation in it (identifiers as hosts in SSH??)
fixed it and added some basic information, why this tool is needed and replaced predecessor telnet
also some basic usage
* Update index.md