Fix +lookup/in-docsets & docsets lookup backend

They were throwing 'cannot find docset' errors.

- Adds new +lookup/in-all-docsets command.
- If a prefix arg is passed to +lookup/in-docsets, it will search all
  docsets in dash-docs-common-docsets.

modules/config/default/+evil-bindings.el

@@ -533,7 +533,8 @@
         :desc "Jump to symbol across buffers" "I" #'imenu-anywhere
         :desc "Jump to link"                  "l" #'ace-link
         :desc "Look up online"                "o" #'+lookup/online-select
-        :desc "Look up in docsets"            "k" #'+lookup/in-docsets
+        :desc "Look up in local docsets"      "k" #'+lookup/in-docsets
+        :desc "Look up in all docsets"        "K" #'+lookup/in-all-docsets
         :desc "Search project"                "p" #'+default/search-project)
 
       ;;; <leader> TAB --- workspace

modules/tools/lookup/autoload/docsets.el

@@ -65,29 +65,36 @@ Docsets must be installed with one of the following commands:
 + `dash-docs-async-install-docset-from-file'
 
 Docsets can be searched directly via `+lookup/in-docsets'."
-  (let ((docsets (dash-docs-buffer-local-docsets)))
-    (when (cl-some #'dash-docs-docset-path docsets)
-      (+lookup/in-docsets identifier docsets)
-      'deferred)))
+  (when-let* ((docsets (cl-remove-if-not #'dash-docs-docset-path (dash-docs-buffer-local-docsets))))
+    (+lookup/in-docsets nil identifier docsets)
+    'deferred))
 
 
 ;;
 ;;; Commands
 
 ;;;###autoload
-(defun +lookup/in-docsets (&optional query docsets)
+(defun +lookup/in-docsets (arg &optional query docsets)
   "Lookup QUERY in dash DOCSETS.
 
 QUERY is a string and docsets in an array of strings, each a name of a Dash
 docset. Requires either helm or ivy.
 
-Use `dash-docs-install-docset' to install docsets."
-  (interactive)
+If prefix ARG is supplied, search all installed installed docsets. They can be
+installed with `dash-docs-install-docset'."
+  (interactive "P")
   (require 'dash-docs)
-  (let ((dash-docs-docsets (or docsets (dash-docs-buffer-local-docsets)))
+  (let ((dash-docs-common-docsets (if arg dash-docs-common-docsets))
+        (dash-docs-docsets (cl-remove-if-not #'dash-docs-docset-path (or docsets dash-docs-docsets)))
         (query (or query (+lookup-symbol-or-region) "")))
     (cond ((featurep! :completion helm)
            (helm-dash query))
           ((featurep! :completion ivy)
            (counsel-dash query))
           ((user-error "No dash backend is installed, enable ivy or helm.")))))
+
+;;;###autoload
+(defun +lookup/in-all-docsets (&optional query)
+  "TODO"
+  (interactive)
+  (+lookup/in-docsets t query))