Update Pre-requisities and troubleshooting section

[mukesh51]

Updated troubleshooting section to notify the "require" error, while invoking ng serve and
modified pre-requisites section to update the order in which angular-cli version is checked.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed, please reply here (e.g. I signed it!) and we'll verify. Thanks.

---

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please let us know the company's name.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed, please reply here (e.g. I signed it!) and we'll verify. Thanks.

---

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please let us know the company's name.

[davideast]

Looks great, @mukesh51! Just two tiny little comments and it's good to go after the CLA is signed.

[davideast]

Can you add that this is just a temporary workaround for the Angular CLI?

[davideast]

(you already got above)

Remove that part as it's a bit redundant.

[googlebot]

CLAs look good, thanks!

[googlebot]

CLAs look good, thanks!