Help prevent supply chain attack: add safer install script (#2627)

## Description:

For safer installations, clean install (ci) should be used, preferably
with added --ignore-scripts. To make it easier for devs, add a npm
script which can be ran by using "npm run inst". Update readme.

Evan agreed here
https://discord.com/channels/1359946986937258015/1360078040222142564/1432085555126206576

"npm run inst" runs `npm ci --ignore-scripts` which installs
dependencies exactly according to the versions in `package-lock.json`
and doesn't run scripts. This can prevent being hit by a supply chain
attack.

Did not re-use the "install" or "ci" npm lifecycle hook, instead used a
similar but still short script name "inst". We can change this to
something like "safe-install" if needed but i assume "inst" will do.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

tryout33

package.json

@@ -18,7 +18,8 @@
     "lint": "eslint",
     "lint:fix": "eslint --fix",
     "prepare": "husky",
-    "gen-maps": "cd map-generator && go run . && npm run format"
+    "gen-maps": "cd map-generator && go run . && npm run format",
+    "inst": "npm ci --ignore-scripts"
   },
   "lint-staged": {
     "**/*": [