Adds session documentation

[zgoldman-r7]

This adds documentation for the SQL/SMB session types. Please let me know if there's anything we need more detail on/should phrase better.

[adfoster-r7]

I think this is missing the changes to the pentesting section of the docs site:

https://docs.metasploit.com/docs/pentesting/
https://docs.metasploit.com/docs/pentesting/metasploit-guide-mysql.html etc

[cgranleese-r7]

I think the comments I have for mssql_login.md are relevant for the rest as well. Adding as much command line output as we can would help as well I think. So if we talk about a command, add the console interactions output to the markdown.

[cgranleese-r7]

Thoughts on maybe adding more steps here on using a login module. I.e copy pasta the full steps so if a user wants to try this then don't have to go elsewhere in the docs to figure out how to use the login modules. I think a single example of lets say mssql_login would be fine.

[zgoldman-r7]

I think this already exists below in 'Scenarios' - do you think we should restructure things to make it more cohesive?

[adfoster-r7]

Adding msf6 to all of the Metasploit console examples will give you syntax highlighting 👀

Suggested change

	```
	```msf6

[cgranleese-r7]

Took another look through this and added some more shuffling I think might make thing clearer. Let me know your thoughts 👍

I added feedback on one markdown again, but it would be relevant to all if you decide to go ahead with the changes.

[adfoster-r7]

Will aim to get this in on Monday since we can do docs releases out of band from the normal release cycle

[adfoster-r7]

I think this is a good first step 🎉

We might want to circle back and reduce some of the verbosity in parts, but we'll be able to come back later with fresh eyes and spot what improvements we want to make then

[cgranleese-r7]

Release Notes

This PR adds documentation for the new SQL and SMB session types.