Add USB stub, add logging using spdlog

.vscode/c_cpp_properties.json

@@ -5,7 +5,10 @@
         "compilerPath": "/usr/bin/clang",
         "cStandard": "c11",
         "cppStandard": "c++17",
-        "compileCommands": "/builddir/compile_commands.json"
+        "compileCommands": "${workspaceFolder}/builddir/compile_commands.json",
+        "browse": {
+          "path": ["${workspaceFolder}"]
+        }
       }
     ],
     "version": 4

.vscode/settings.json

@@ -78,6 +78,10 @@
                             "typeindex": "cpp",
                             "typeinfo": "cpp",
                             "valarray": "cpp",
-                            "variant": "cpp"
+                            "variant": "cpp",
+                            "csignal": "cpp",
+                            "any": "cpp",
+                            "regex": "cpp",
+                            "future": "cpp"
                         }
 }