feat: check for compat with Edge 79+, Node 12+

These versions have been selected for availability of `TextDecoder`.
(But not whether ESM is supported, since bundlers can take care of that
problem)

Also document support for MS Edge 79+ and Node.js v12+

README.md

@@ -4,9 +4,11 @@ A lightweight Adobe Photoshop .psd/.psb file parser in typescript with zero-depe
 
 ## Browser Support
 
-| Chrome | Firefox | Safari | Internet Explorer |
-| :----: | :-----: | :----: | :---------------: |
-|   38   |   20    |  10.1  |   Not Supported   |
+| Chrome | Firefox | Safari | Edge | Node |
+| :----: | :-----: | :----: | :--: | :--: |
+|   38   |   20    |  10.1  |  79  |  12  |
+
+\*Internet Explorer is not supported
 
 ## Installation
 

package.json

@@ -34,7 +34,9 @@
   "browserslist": [
     "chrome >= 38",
     "firefox >= 20",
-    "safari >= 10.1"
+    "safari >= 10.1",
+    "edge >= 79",
+    "node >= 12"
   ],
   "devDependencies": {
     "@types/jest": "^27.0.3",