Extract tsconfig.src.base.json from tsconfig.base.json

`tsconfig.base.json` includes settings that apply to ALL typescript in
the project (including tests and docsgen), while
`tsconfig.src.base.json` includes settings that should only apply to the
source code of the main library.

This fixes the `include` and `exclude` fields intended for library
compilation being applied to the `tests` and `docsgen` folders, which
made those folders actually just compile the library instead of their
actual code.

Author: ItsHarper

tsconfig.base.json

@@ -19,13 +19,5 @@
             "es2015",
             "es2015.core"
         ]
-    },
-    "include": [
-        "src"
-    ],
-    "exclude": [
-        "dist",
-        "node_modules",
-        "test"
-    ]
-}
+    }
+}

tsconfig.cjs.json

@@ -1,8 +1,8 @@
 {
-    "extends": "./tsconfig.base.json",
+    "extends": "./tsconfig.src.base.json",
     "compilerOptions": {
         "module": "commonjs",
         "outDir": "./dist/cjs",
         "target": "ES2015"
     }
-}
+}

tsconfig.esm.json

@@ -1,8 +1,8 @@
 {
-    "extends": "./tsconfig.base.json",
+    "extends": "./tsconfig.src.base.json",
     "compilerOptions": {
         "module": "es6",
         "outDir": "./dist/esm",
         "target": "es6"
     }
-}
+}

tsconfig.src.base.json

@@ -0,0 +1,11 @@
+{
+  "extends": "./tsconfig.base.json",
+  "include": [
+    "src"
+  ],
+  "exclude": [
+    "dist",
+    "node_modules",
+    "test"
+  ]
+}