Variable metadata connector documentation

[xlxs4]

In the documentation page there's no mention of the two out of the three connect metadata. Equality and Stream are not mentioned/explained in the docs, only Flow is. The available metadata are here.
You can also mention what the default behavior is, if none of the three are explicitly passed.

From the respective Discourse thread here:

It’s the same as Modelica:

• Equality variables connect by making values equal. For example, connecting pins in an electrical circuit makes the voltages equal at the junction.
• Flow variables connect by making the sum zero. For example, connecting pins in an electrical circuit makes the current sum to zero at the junction.
• Stream connectors are for fluids. See 15 Stream Connectors‣ Modelica® Language Specification version 3.6-dev and https://build.openmodelica.org/Documentation/Modelica%204.0.0/Resources/Documentation/Fluid/Stream-Connectors-Overview-Rationale.pdf.

[ChrisRackauckas]

This is all documented now.