docs/faq: add "Why sharp-quote functions"

docs/faq.org

@@ -51,6 +51,8 @@
   - [[#why-do-non-evil-users-get-expand-region-but-not-evil-users][Why do non-evil users get expand-region, but not evil users?]]
   - [[#why-not-use-exec-path-from-shell-instead-of-doom-env][Why not use exec-path-from-shell instead of ~doom env~?]]
   - [[#why-wsbutler-over-delete-trailing-whitespace-or-whitespace-cleanup][Why wsbutler over delete-trailing-whitespace or whitespace-cleanup?]]
+- [[#emacs-lisp][Emacs Lisp]]
+  - [[#why-do-you-quote-some-symbols-with-symbol][Why do you quote some symbols with ~#'symbol~?]]
 - [[#common-issues][Common Issues]]
   - [[#i-get-the-vanilla-emacs-splash-screen-at-startup][I get the vanilla Emacs splash screen at startup]]
   - [[#i-see-a-blank-scratch-buffer-at-startup][I see a blank scratch buffer at startup]]
@@ -989,6 +991,19 @@ cleanup work.
 
 In any case, if you had used =ws-butler= from the beginning, trailing whitespace
 and newlines would never be a problem!
+* Emacs Lisp
+** Why do you quote some symbols with ~#'symbol~?
+~#'symbol~ is short for ~(function symbol)~, the same way ~'symbol~ is short for
+~(quote symbol)~.
+
+In elisp there is no /functional/ difference between the two syntaxes, but the
+sharp-quote does hint to the byte-compiler that "this symbol refers to a
+function", which it can perform additional checks on when the code is
+byte-compiled.
+
+My reason for using it is to make it explicit to readers how I intend (or
+expect) the symbol to be used. No sharp-quote means I'm using the symbol as a
+literal data value.
 
 * Common Issues
 ** I get the vanilla Emacs splash screen at startup