fast start instructions (#142)

* fast start instructions

* Update GETTING-STARTED.md

Co-authored-by: Nikita Shulga <[email protected]>

* Update GETTING-STARTED.md

Co-authored-by: Nikita Shulga <[email protected]>

* Update GETTING-STARTED.md

Co-authored-by: Nikita Shulga <[email protected]>

---------

Co-authored-by: Nikita Shulga <[email protected]>

Author: mikekgfb

GETTING-STARTED.md

@@ -0,0 +1,40 @@
+
+Instructions, as suggested by @Orion. (Consider creating a version
+with text interspersed as Google Colab and link it here at the top.)
+
+```
+python3 -m pip install --user virtualenv
+python3 -m virtualenv .llama-fast
+source .llama-fast/bin/activate
+git clone https://github.com/pytorch/torchat.git
+cd llama-fast
+git submodule sync
+git submodule update --init
+
+# If we need PyTorch nightlies
+pip3 install --pre torch  --index-url https://download.pytorch.org/whl/nightly/cpu
+# Otherwise
+# pip3 install torch
+
+pip install sentencepiece huggingface_hub
+# Eventually should be (when Dave has the PyPI packages)
+# pip install sentencepiece huggingface_hub executorch
+# I had some issues with the pytorch submodule not downloading from ExecuTorch - not sure why
+
+# To download Llama 2 models, go to https://huggingface.co/meta-llama/Llama-2-7b and go through steps to obtain access.
+
+# Once approved, login with
+huggingface-cli login
+# You will be asked for a token from https://huggingface.co/settings/tokens
+
+# Set the model and paths for stories15M as an example to test things on desktop and mobile
+MODEL_NAME=stories15M
+MODEL_PATH=checkpoints/${MODEL_NAME}/stories15M.pt
+MODEL_DIR=~/llama-fast-exports
+
+# Could we make this stories15 instead?
+export MODEL_DOWNLOAD=meta-llama/Llama-2-7b-chat-hf
+./scripts/prepare.sh $MODEL_DOWNLOAD
+python generate.py --compile --checkpoint-path ${MODEL_PATH} --prompt "Hello, my name is" --device {cuda,cpu,mps}
+
+```