Reorganize & rethink help commands

Changes:
- Move <help>da to <help>u & <help>du = lookup docs for an autodef
- Rebind <help>dC = goto private init file (and jump to doom! block)
- Add <help>u & <help>du = lookup docs on an autodef
- Add <help>dl = text search on all packages in load-path
- Add <help>dL = text search on all load el files

New <help>p prefix for package help commands:
- <help>dpc = jump to a config block for a package
- <help>dpd = goto private packages.el file
- <help>dph = open a package's homepage (its repo or on melpa)
- <help>dpp = lookup docs on a package (including Doom info; what
    module(s) install package, where it is configured, etc)

core/autoload/config.el

@@ -26,8 +26,9 @@
   (doom-project-find-file doom-private-dir))
 
 ;;;###autoload
-(defun doom/goto-doomblock ()
-  "Open your private init.el and go to your `doom!' block."
+(defun doom/goto-private-init-file ()
+  "Open your private init.el file.
+And jumps to your `doom!' block."
   (interactive)
   (find-file (expand-file-name "init.el" doom-private-dir))
   (goto-char
@@ -37,13 +38,13 @@
        (point))))
 
 ;;;###autoload
-(defun doom/goto-config-file ()
+(defun doom/goto-private-config-file ()
   "Open your private config.el file."
   (interactive)
   (find-file (expand-file-name "config.el" doom-private-dir)))
 
 ;;;###autoload
-(defun doom/goto-packages-file ()
+(defun doom/goto-private-packages-file ()
   "Open your private packages.el file."
   (interactive)
   (find-file (expand-file-name "packages.el" doom-private-dir)))