Add line type beta rendering of flowcharts

[knsv]

Currently support for:

===
-.-

Is not in place

[vantoan8x]

Dear @knsv,

currently mermaid being support:

—-
-.-
===
=.= (yet, will support?)

—>
-.->
==>
=.=> (yet, will support?)

yet support:

—x
-.-x
==x
=.=x

—o
-.-o
==o
=.=o

and two way of arrow/mark styles. <—>, ...
and all invert direction of arrow.

note:

invert direction is not reversed write A —> B alternatted by B —> A, it must be A <— B, because the direct of whole direction of flow chart keep correctly.

Regards.
Tom.