Update root README with architecture, providers, and onboarding links

[Copilot]

The issue asks to refresh the README with the new architectural direction, provider list, getting-started guidance, benchmark pointers, and a link to the wiki paper list. This PR updates the root README to include those items in a concise, scannable format.

• Architecture & components
  • Documented the Rust workspace layout across base/numerics, core algorithm, providers/storage, and tooling.
• Providers overview
  • Added a focused list of provider implementations with crate/feature references.
• Onboarding & references
  • Added getting-started steps and links to benchmark documentation plus the wiki paper list.

Example excerpt:

## Getting started

1. Install Rust using the toolchain in `rust-toolchain.toml`.
2. Build the workspace: `cargo build`.
3. Run tests: `cargo test`.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Update README</issue_title>
<issue_description>## Is your feature request related to a problem? Please describe.
We need to update the README with the following

Describe the solution you'd like

Add the following

• The new architectural direction.
• A list of providers
• Getting started
• pointers to benchmarks
• pointer to paper in Wiki
  </issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Update README #739

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[suri-kumkaran]

We should also update these on the wiki/home of the repo.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.00%. Comparing base (354df71) to head (526ac51).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #740   +/-   ##
=======================================
  Coverage   89.00%   89.00%           
=======================================
  Files         428      428           
  Lines       78294    78294           
=======================================
  Hits        69686    69686           
  Misses       8608     8608           

Flag	Coverage Δ
miri	89.00% <ø> (ø)
unittests	89.00% <ø> (ø)

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