new icon: matlab (line) (#640)

* Add matlab-line

* Fixed issues reported by check svg bot

* optimisation for svg (#643)

Co-authored-by: Clemens Bastian <8781699+amacado@users.noreply.github.com>
Co-authored-by: David Leal <halfpacho@gmail.com>

Author: 3 people

devicon.json

@@ -2452,10 +2452,12 @@
         "versions": {
           "svg": [
             "original",
-            "plain"
+            "plain",
+            "line"
           ],
           "font": [
-            "plain"
+            "plain",
+            "line"
           ]
         },
         "color": "#6dd0c7",