[docs]: Revamp embedchain docs

[deshraj]

Description

Updating docs to include the following changes:

• Add yaml config examples for different configurations like llms, vector databases, and embedding models
• Add docs about configuring different params for each component in embedchain
• Clean up old stale docs which is no longer relevant

Type of change

Please delete options that are not relevant.

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (does not change functionality, e.g. code style improvements, linting)
• Documentation update

How Has This Been Tested?

• Unit Test

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Files	Coverage Δ
embedchain/apps/app.py	100.00% <ø> (ø)
embedchain/apps/open_source_app.py	100.00% <ø> (ø)
embedchain/apps/person_app.py	51.35% <100.00%> (ø)
embedchain/bots/base.py	100.00% <100.00%> (ø)
embedchain/config/__init__.py	100.00% <100.00%> (ø)
embedchain/embedchain.py	72.76% <ø> (ø)
embedchain/embedder/vertexai.py	53.84% <100.00%> (ø)
embedchain/factory.py	93.02% <ø> (ø)
embedchain/llm/base.py	76.47% <100.00%> (ø)
embedchain/llm/huggingface.py	93.10% <100.00%> (ø)
... and 3 more

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