[web-search] Add `Melpa Package Search` option

layers/+web-services/search-engine/README.org

@@ -43,6 +43,7 @@ This layer adds support for the [[https://github.com/hrs/engine-mode][Search Eng
 - Python Package Index
 - Python Docs
 - C++ Reference
+- Melpa
 
 * Install
 To use this configuration layer, add it to your =~/.spacemacs=. You will need to

layers/+web-services/search-engine/packages.el

@@ -11,9 +11,8 @@
 
 ;; List of all packages to install and/or initialize. Built-in packages
 ;; which require an initialization must be listed explicitly in the list.
-(setq search-engine-packages
-      '(
-        engine-mode))
+(defconst search-engine-packages
+  '(engine-mode))
 
 
 (defun search-engine/init-engine-mode ()
@@ -97,6 +96,9 @@
               (wolfram-alpha
                :name "Wolfram Alpha"
                :url "https://www.wolframalpha.com/input/?i=%s")
+              (melpa
+               :name "Melpa Package Search"
+               :url "https://melpa.org/#/?q=%s")
               (ctan
                :name "CTAN"
                :url "https://ctan.org/search?phrase=%s")