Improve model card with project page, code link, and sample usage

This PR enhances the model card by adding a link to the project page and the GitHub repository, making it easier for users to find more information and the code. It also includes a sample usage snippet directly from the GitHub README to demonstrate how to use the model.

README.md

@@ -13,6 +13,9 @@ This is a model from the paper [Thera: Aliasing-Free Arbitrary-Scale Super-Resol
 It enables SOTA arbitrary-scale super-resolution, leveraging a built-in analytically correct observation model 
 for anti-aliasing when moving across scales.
 
+Project page: https://therasr.github.io
+Code: https://github.com/prs-eth/thera
+
 ## Model Details
 
 - **Description**: This model can be used to enable super-resolution of single images at arbitrary, non-integer scaling factors.
@@ -20,6 +23,12 @@ for anti-aliasing when moving across scales.
 - **Variant**: `Pro`
 - **Training Dataset**: `DIV2K`
 
+## Sample Usage
+
+Super-resolve any image with:
+```bash
+./super_resolve.py IN_FILE OUT_FILE --scale 3.14 --checkpoint thera-rdn-pro.pkl
+```
 
 ## License