Add more api demos (#1845)

* Added function Demos
* Added use-package demos
* Some corrections
* Fix duplicated use-package! type

core/core-keybinds.el

@@ -419,18 +419,7 @@ Properties
   :unless [CONDITION] [...]
 
   Any of the above properties may be nested, so that they only apply to a
-  certain group of keybinds.
-
-Example
-  (map! :map magit-mode-map
-        :m  \"C-r\" 'do-something           ; C-r in motion state
-        :nv \"q\" 'magit-mode-quit-window   ; q in normal+visual states
-        \"C-x C-r\" 'a-global-keybind
-        :g \"C-x C-r\" 'another-global-keybind  ; same as above
-
-        (:when IS-MAC
-         :n \"M-s\" 'some-fn
-         :i \"M-o\" (lambda (interactive) (message \"Hi\"))))"
+  certain group of keybinds."
   (doom--map-process rest))
 
 (provide 'core-keybinds)

core/core-lib.el

@@ -301,10 +301,6 @@ If N and M = 1, there's no benefit to using this macro over `remove-hook'.
 (defmacro setq-hook! (hooks &rest var-vals)
   "Sets buffer-local variables on HOOKS.
 
-  (setq-hook! 'markdown-mode-hook
-    line-spacing 2
-    fill-column 80)
-
 \(fn HOOKS &rest [SYM VAL]...)"
   (declare (indent 1))
   (macroexp-progn

core/core-modules.el

@@ -425,26 +425,17 @@ two extra properties:
 :after-call SYMBOL|LIST
   Takes a symbol or list of symbols representing functions or hook variables.
   The first time any of these functions or hooks are executed, the package is
-  loaded. e.g.
-
-  (use-package! projectile
-    :after-call (pre-command-hook after-find-file dired-before-readin-hook)
-    ...)
+  loaded.
 
 :defer-incrementally SYMBOL|LIST|t
   Takes a symbol or list of symbols representing packages that will be loaded
   incrementally at startup before this one. This is helpful for large packages
   like magit or org, which load a lot of dependencies on first load. This lets
   you load them piece-meal during idle periods, so that when you finally do need
-  the package, it'll load quicker. e.g.
+  the package, it'll load quicker.
 
   NAME is implicitly added if this property is present and non-nil. No need to
-  specify it. A value of `t' implies NAME, e.g.
-
-  (use-package! abc
-    ;; This is equivalent to :defer-incrementally (abc)
-    :defer-incrementally t
-    ...)"
+  specify it. A value of `t' implies NAME."
   (declare (indent 1))
   (unless (or (memq name doom-disabled-packages)
               ;; At compile-time, use-package will forcibly load packages to