add an installation example for straight.el without use-package

[erikLundstedt]

here is what i got

(straight-use-package
 '(org-logseq :type git :host github :repo "llcc/org-logseq" :files ("*")))
(customize-set-variable 'org-logseq-dir "~/logseq")

I can confirm that it works(for me atleast)