Merge branch 'docs' of github.com:relari-ai/continuous-eval into docs

docs/src/content/docs/getting-started/installation.md

@@ -3,13 +3,26 @@ title: Installation
 description: How to install continuous-eval
 ---
 
-`continuous-eval` is provided as an open-source Python package. To install it, run the following command:
+`continuous-eval` is provided as an open-source Python package. 
+To install it, run the following command:
 
 ```bash
 python3 -m pip install continuous-eval
 ```
 
-if you want to install from source
+the package offers optional extras for additional functionality:
+
+- `anthropic` to support Anthropic's Claude model
+- `gemini` to support Google's Gemini model
+- `generators` to support automatic dataset generation
+
+with PIP you can install any combination of them with:
+
+```bash
+pip install continuous-eval[anthropic,gemini,generators]
+```
+
+Otherwise you can install continuous-eval from source
 
 ```bash
 git clone https://github.com/relari-ai/continuous-eval.git && cd continuous-eval
@@ -21,11 +34,6 @@ continuous-eval is tested on Python 3.9 and 3.11.
 **Optional:**
 If you want to run LLM-based metrics, continuous-eval supports OpenAI, Anthropic and Google models, which require API keys:
 
-- `OPENAI_API_KEY` 
+- `OPENAI_API_KEY`
 - `ANTHROPIC_API_KEY` (optional)
 - `GEMINI_API_KEY` (optional)
-
-```bash
-import os
-os.environ["OPENAI_API_KEY"] = "your-openai-key"
-```