Syntax: relationship + arrow

Support the following syntax for aspects (term to describe a “subject - relationship - object” phrase)

- [[some evidence]]
    - [[supports]] ->
        - [[a claim]]
- [[claim]]
    - <- [[supports]]
        - [[some evidence 1]]
        - [[some evidence 2]]
a claim (on the page)
- <- [[supports]]
	- [[some evidence]]
some evidence (on the page)
- [[supports]] ->
	- [[a claim]]

Pros

The arrow solves the problem of dealing with complements

Arrow provides a language agnostic relationship direction indicator

Uses existing block hierarchy structure already core to Logseq

Familiar to Discourse Graph users

Cons

Less readable when the arrow is pointing “backwards” since default is not to create a separate phrase as the complement