Fix Build-in README installation command. Add required ElasticSearch params since 2.4. Add new line concatenation character

Author: progreg

phpserver/README.md

@@ -17,11 +17,12 @@ Without a router script, that is not possible via the php built-in server.
 Please read how to install Magento using the <a href="https://devdocs.magento.com/guides/v2.4/install-gde/install/cli/install-cli.html" target="_blank">command line</a>. An example follows:
 
 ```
-php bin/magento setup:install --base-url=http://127.0.0.1:8082 
---db-host=localhost --db-name=magento --db-user=magento --db-password=magento
---admin-firstname=Magento --admin-lastname=User [email protected]
---admin-user=admin --admin-password=admin123 --language=en_US
---currency=USD --timezone=America/Chicago --use-rewrites=1
+php bin/magento setup:install --base-url=http://127.0.0.1:8082 \
+--db-host=localhost --db-name=magento --db-user=magento --db-password=magento \
+--admin-firstname=Magento --admin-lastname=User [email protected] \
+--admin-user=admin --admin-password=admin123 --language=en_US \
+--currency=USD --timezone=America/Chicago --use-rewrites=1 \
+--search-engine=elasticsearch7 --elasticsearch-host=es-host.example.com --elasticsearch-port=9200
 ```
 
 Notes: