Added introslider and onboarding for new users

[jaivsh]

Adding Introslider and Onboarding for new users!

Closes #89

Description

I've added onboarding and intro slider for first-time users, which would make them familiar with the usability of the app and it's features. This also includes creation of the suitable graphic images and other secondary stuff. For this, i've used the following packages from pub.dev:

intro_slider shared_preferences IsFirstRun

Screenshots

Checklist

• [x] My code adheres to the established style guidelines of the project.
• [x] I have included comments in areas that may be difficult to understand.
• [x] My changes have not introduced any new warnings.
• [x] I have conducted a self-review of my code.

[jaivsh]

Hi @m0hit-kumar can you please review this PR? Thanks!

[jaivsh]

Hi @m0hit-kumar I've removed all swift files, which were causing the tests to fail. Hence, can you please check them again?

[jaivsh]

Hi @m0hit-kumar I've recently chcked with the GSSOC team: the way in which your codeql is designed is wrong. The codeql has identified c++ and swift as your project's primary languages, which is not correct. Your project is based in flutter, so Dart turns out to be your primary language. Hence, the codeql should be set up in dart, and not in cpp or swift. This is the reason why it is failing those checks. in the PR. Hence, I'd require please review it. Thanks!

[m0hit-kumar]

Hi @m0hit-kumar I've recently chcked with the GSSOC team: the way in which your codeql is designed is wrong. The codeql has identified c++ and swift as your project's primary languages, which is not correct. Your project is based in flutter, so Dart turns out to be your primary language. Hence, the codeql should be set up in dart, and not in cpp or swift. This is the reason why it is failing those checks. in the PR. Hence, I'd require please review it. Thanks!

i see that, do one thing resolve the conflicts and I will merge your PR

[jaivsh]

@m0hit-kumar resolved conflicts, please merge!