Font-Awesome added (read below)

The drupal/fontawesome package does not require the Font Awesome library
on its own, so we have to hack it around with custom install path to
enforce the package into the Drupal libraries folder.

oomphinc/composer-installers-extender#26
https://www.drupal.org/project/fontawesome/issues/2839928

composer.json

@@ -55,7 +55,9 @@
         "drupal/redirect": "^1.6",
         "drupal/simplemde": "^1.0@alpha",
         "drush/drush": "^10.0",
-        "league/commonmark": "^1.5"
+        "fortawesome/font-awesome": "5.13.1",
+        "league/commonmark": "^1.5",
+        "oomphinc/composer-installers-extender": "^2.0"
     },
     "conflict": {
         "drupal/drupal": "*"
@@ -76,13 +78,17 @@
             },
             "drupal/simplemde": {
                 "#12 WIP added support for image upload": "https://patch-diff.githubusercontent.com/raw/nuvoleweb/simplemde/pull/12.patch"
+            },
+            "oomphinc/composer-installers-extender": {
+                "Fix custom install path behavior": "https://github.com/neclimdul/composer-installers-extender/commit/92ea53551ab68041ac47b5e8799130b79779652a.patch"
             }
         },
         "drupal-scaffold": {
             "locations": {
                 "web-root": "web/"
             }
         },
+        "installer-types": ["library"],
         "installer-paths": {
             "web/core": [
                 "type:drupal-core"
@@ -107,6 +113,9 @@
             ],
             "web/themes/custom/{$name}": [
                 "type:drupal-custom-theme"
+            ],
+            "web/libraries/fontawesome": [
+                "fortawesome/font-awesome"
             ]
         },
         "drupal-core-project-message": {