add documentation for MD flowsheet

[ElmiraShamlou]

addresses #1219 for MD

(replace this with the issue # fixed or resolved, if no issue exists then a brief statement of what this PR does)

Summary/Motivation:

Changes proposed in this PR:

Legal Acknowledgement

By contributing to this software project, I agree to the following terms and conditions for my contribution:

1. I agree my contributions are submitted under the license terms described in the LICENSE.txt file at the top level of this directory.
2. I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.94%. Comparing base (b1a84b4) to head (f6b2e6b).
Report is 29 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1444   +/-   ##
=======================================
  Coverage   93.94%   93.94%           
=======================================
  Files         310      310           
  Lines       33206    33206           
=======================================
  Hits        31194    31194           
  Misses       2012     2012           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[MarcusHolly]

Other than one last typo, LGTM

[kurbansitterley]

Mostly formatting changes in a table, I made suggestions where possible.

Only one clarifying question at the end.

[kurbansitterley]

Suggested change

	"Maximum outlet temperature", "90", "°C"
	"Maximum outlet temperature", "363", ":math:`\text{K}`"

[kurbansitterley]

oops didn't realize Adam approved while I was reviewing.

[kurbansitterley]

LGTM