README: better setup instructions for developers for pip and poetry

Give folks options + explicit instructions for installing with poetry or pip.

Author: Stonelinks

README.md

@@ -141,6 +141,17 @@ To get started, clone the repository and install the package in development mode
 
 ```bash
 git clone --recurse-submodules [email protected]:abetlen/llama-cpp-python.git
+
+# Install with pip
+pip install -e .
+
+# if you want to use the fastapi / openapi server
+pip install -e .[server]
+
+# If you're a poetry user, installing will also include a virtual environment
+poetry install --all-extras
+. .venv/bin/activate
+
 # Will need to be re-run any time vendor/llama.cpp is updated
 python3 setup.py develop
 ```

poetry.lock

@@ -15,7 +15,9 @@ include = [
 [tool.poetry.dependencies]
 python = "^3.8.1"
 typing-extensions = "^4.5.0"
-
+uvicorn = { version = "^0.21.1", optional = true }
+fastapi = { version = "^0.95.0", optional = true }
+sse-starlette = { version = "^1.3.3", optional = true }
 
 [tool.poetry.group.dev.dependencies]
 black = "^23.3.0"
@@ -27,6 +29,9 @@ pytest = "^7.3.1"
 httpx = "^0.24.0"
 scikit-build = "0.13"
 
+[tool.poetry.extras]
+server = ["uvicorn", "fastapi", "sse-starlette"]
+
 [build-system]
 requires = [
     "setuptools>=42",