gritlm : add initial README.md (#6086)

* gritlm: add initial README.md to examples/gritlm

This commit adds a suggestion for an initial README.md for the gritlm
example.

Signed-off-by: Daniel Bevenius <daniel.bevenius@gmail.com>

* squash! gritlm: add initial README.md to examples/gritlm

Use the `scripts/hf.sh` script to download the model file.

Signed-off-by: Daniel Bevenius <daniel.bevenius@gmail.com>

* squash! gritlm: add initial README.md to examples/gritlm

Fix editorconfig-checker error in examples/gritlm/README.md.

Signed-off-by: Daniel Bevenius <daniel.bevenius@gmail.com>

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Signed-off-by: Daniel Bevenius <daniel.bevenius@gmail.com>