Update/docs landing page (#555)

* huge docs update incoming

* more updates on comparisons

* remove emojis

* cleaning up how it looks and making it make sense

* More updates to making sure things are up-to-date with the new pyhealth2

* dataset table fix + documentation icon fix

* make key features section less intrusive

Again terrible git practice, but no one else is working with me on this atm lol.

---------

Co-authored-by: jhnwu3 <knightsofthe8@gmail.com>

Author: jhnwu3

docs/index.rst

@@ -9,8 +9,7 @@ Welcome to PyHealth
 
 Build, test, and deploy healthcare machine learning models with ease. PyHealth makes healthcare AI development accessible to researchers, data scientists, and medical practitioners.
 
-Key Features
-------------------
+**Key Features**
 
 - Modular 5-stage pipeline for healthcare ML
 - Healthcare-first: medical codes and clinical datasets (MIMIC, eICU, OMOP)
@@ -19,10 +18,14 @@ Key Features
 - Fast (3x faster than pandas) data processing for quick experimentation
 
 
-.. image:: https://readthedocs.org/projects/pyhealth/badge/?version=latest
+.. image:: https://app.readthedocs.org/projects/pyhealth/badge/?version=latest&style=flat
    :target: https://pyhealth.readthedocs.io/en/latest/
    :alt: Documentation status
 
+.. image:: https://img.shields.io/readthedocs/pyhealth?logo=readthedocs&label=docs&version=latest
+   :target: https://pyhealth.readthedocs.io/en/latest/
+   :alt: Docs
+
 .. image:: https://img.shields.io/badge/Discord-Join-5865F2?logo=discord&logoColor=white
    :target: https://discord.gg/mpb835EHaX
    :alt: Discord
@@ -35,7 +38,6 @@ Key Features
    :target: https://pypi.org/project/pyhealth/
    :alt: PyPI version
 
-
 .. image:: https://img.shields.io/github/stars/yzhao062/pyhealth.svg
    :target: https://github.com/sunlabuiuc/pyhealth/stargazers
    :alt: GitHub stars

docs/why_pyhealth.rst

@@ -54,22 +54,40 @@ Access cutting-edge healthcare AI models without complex implementation:
 
 Work with the most important healthcare datasets out of the box:
 
-.. table:: **Supported Datasets**
-   :widths: auto
-
-   ===================  ========================================  =======================================
-   Dataset              Information                               Year
-   ===================  ========================================  =======================================
-   **MIMIC-III**        Critical care database (40K+ patients)   2016
-   **MIMIC-IV**         Updated critical care database (300k+ patients)            2020  
-   **eICU**             Multi-center ICU database                 2018
-   **OMOP-CDM**         Standardized healthcare data format      Ongoing
-   **EHRShot**          Few-shot EHR benchmarking dataset        2023
-   **COVID19-CXR**      COVID-19 chest X-ray image dataset       2020
-   **SleepEDF**         Sleep study recordings                    2018
-   **SHHS**             Sleep Heart Health Study                  2016
-   **ISRUC**            Sleep disorder database                   2016
-   ===================  ========================================  =======================================
+.. list-table:: Supported Datasets
+   :widths: 22 50 12
+   :header-rows: 1
+
+   * - Dataset
+     - Information
+     - Year
+   * - MIMIC-III
+     - Critical care database (40K+ patients)
+     - 2016
+   * - MIMIC-IV
+     - Updated critical care database (300k+ patients)
+     - 2020
+   * - eICU
+     - Multi-center ICU database
+     - 2018
+   * - OMOP-CDM
+     - Standardized healthcare data format
+     - Ongoing
+   * - EHRShot
+     - Few-shot EHR benchmarking dataset
+     - 2023
+   * - COVID19-CXR
+     - COVID-19 chest X-ray image dataset
+     - 2020
+   * - SleepEDF
+     - Sleep study recordings
+     - 2018
+   * - SHHS
+     - Sleep Heart Health Study
+     - 2016
+   * - ISRUC
+     - Sleep disorder database
+     - 2016
 
 🤖 **Comprehensive Model Library**
 ==================================