issue #6 - add integration-test workflow + readme #3

	name: Integration Tests

	on:
	pull_request:
	workflow_dispatch: # allow manual trigger

	jobs:
	test-action:
	runs-on: ubuntu-latest

	services:
	mongodb:
	image: mongo
	ports:
	- 27017:27017

	steps:
	- uses: actions/checkout@v3

	# Test local action
	- name: Test local action
	uses: ./

	- name: Verify installation
	run: \|
	# mongo-tools
	mongodump --version
	mongorestore --version

	# mongo-shell
	mongosh --version

	- name: Functional test
	run: \|
	echo "💥 Create test user"
	mongosh admin --eval 'db.createUser({user:"testuser",pwd:"testpass",roles:[{role:"readWrite",db:"testdb"}]});'

	echo "💥 Create testdb with testcollection and one doc"
	mongosh testdb --quiet --eval 'db.testcollection.insertOne({test: "data"});'

	echo "💥 mongodump"
	mongodump --db testdb --out ./dump

	echo "🔎 check dump exists"
	if [ ! -d "./dump/testdb" ]; then
	echo "Dump failed"
	exit 1
	fi

	echo "💥 Drop db"
	mongosh testdb --eval 'db.dropDatabase();'

	echo "💥 Restore it"
	mongorestore ./dump

	echo "🔎 check restored data"
	COUNT=$(mongosh testdb --quiet --eval 'db.testcollection.countDocuments()')
	if [ "$COUNT" != "1" ]; then
	echo "Restore verification failed - count:$COUNT"
	exit 1
	fi

Provide feedback