Fix footprints for Mini PCIe and switches

(set pads for mounting and case to GND)
Set PCB to 4 layer with 0.5 OZ (0,017mm) copper on the inner layers
Start sorting the footprints on the PCB
TO-DO: check footprints of Y1 and Y2, they seem way too large

Hardware/KiCad/DIY_Router.kicad_pro

@@ -39,9 +39,9 @@
         "other_text_thickness": 0.15,
         "other_text_upright": false,
         "pads": {
-          "drill": 0.8,
-          "height": 1.27,
-          "width": 2.54
+          "drill": 0.0,
+          "height": 0.9,
+          "width": 1.3
         },
         "silk_line_width": 0.1,
         "silk_text_italic": false,
@@ -668,7 +668,7 @@
         "uuid": "e7060ada-4117-4611-abe2-1a97a47c74c4"
       }
     ],
-    "used_designators": "U6,SW1-4,R19,R23-25,#PWR55,#PWR68-69,#PWR74,#PWR79,D2",
+    "used_designators": "J1,U6,SW1-4,TP2-7,R19,R23-25,#PWR1,#PWR55,#PWR68-70,#PWR74,#PWR79,D2",
     "variants": []
   },
   "sheets": [