refactor readme according to new website

[Priyansi]

Related to #2302

Description: Removed large chunks of information in README with links to the new website.

Check list:

• [ ] New tests are added (if a new feature is added)
• [ ] New doc strings: description and/or example code are in RST format
• [ ] Documentation is updated (if required)

[vfdev-5]

Thanks for the PR @Priyansi Let's make it even more concise, let's remove the following sections:

• User feedback (we do not have any feedback of that type :) since then => remove)
• Additional Materials, and update https://pytorch-ignite.ai/talks/ if needed
• Table of contents

Let's reduce even more:

• Projects using Ignite

Let's rework:

• Why Ignite?
• Other Documentation -> Documentation and update links

[bibhabasumohapatra]

from user and learner viewpoint, I wanted to add a request, can you please change https://github.com/bibhabasumohapatra/ignite#tldr IDE theme and use a much cool looking GIF.
only a suggestion, it attracts more eyes and users.

[Priyansi]

Thanks for the suggestion @bibhabasumohapatra ! Did you have something in mind?

[sdesrozis]

Maybe it misses a link to https://PyTorch-ignite.ai

Or maybe I missed it 😉

[vfdev-5]

@sdesrozis please also review

[sdesrozis]

Maybe "Why Ignite" could be replaced by a sort of "How To" ? Although I think it can be removed if we extend the library short description.

Otherwise it looks good to me !

[Priyansi]

Maybe "Why Ignite" could be replaced by a sort of "How To" ? Although I think it can be removed if we extend the library short description.

Just to clarify, How To means different use cases for the library right?

[vfdev-5]

@Priyansi let's merge and reduce "Documentation and Getting Started" and "Other Documentation"

[Priyansi]

@Priyansi let's merge and reduce "Documentation and Getting Started" and "Other Documentation"

@vfdev-5 I'm not sure how to reduce this section further. The order for getting started is necessary, Apart from that, should I scrape the issues, discussions and roadmap links?

[vfdev-5]

@Priyansi let's merge and reduce "Documentation and Getting Started" and "Other Documentation"

@vfdev-5 I'm not sure how to reduce this section further. The order for getting started is necessary, Apart from that, should I scrape the issues, discussions and roadmap links?

Here is an example:

# Documentation and Getting Started

The website for the library containing an overview can be found at: https://pytorch-ignite.ai/. Here is the order we suggest for getting started:

1. [Getting Started Guide for essentials of setting up a project](https://pytorch-ignite.ai/tutorials/beginner/01-getting-started/)
2. [Tutorials for the beginner, intermediate and advanced user](https://pytorch-ignite.ai/tutorials/)
3. [How-to Guides for code recipes with minimal explanation](https://pytorch-ignite.ai/how-to-guides/)
4. [Concepts to understand the essence of the library](https://pytorch-ignite.ai/concepts/)
5. [Stable](https://pytorch.org/ignite/) / [Development](https://pytorch.org/ignite/master/) API documentations

[Priyansi]

@vfdev-5 is it okay now?