infra: cleanup docs build (#21134)

Refactors the docs build in order to:
- run the same `make build` command in both vercel and local build
- incrementally build artifacts in 2 distinct steps, instead of building
all docs in-place (in vercel) or in a _dist dir (locally)

Highlights:
- introduces `make build` in order to build the docs
- collects and generates all files for the build in
`docs/build/intermediate`
- renders those jupyter notebook + markdown files into
`docs/build/outputs`

And now the outputs to host are in `docs/build/outputs`, which will need
a vercel settings change.

Todo:
- [ ] figure out how to point the right directory (right now deleting
and moving docs dir in vercel_build.sh isn't great)

docs/vercel_build.sh

@@ -2,39 +2,9 @@
 
 set -e
 
-yum -y update
-yum install gcc bzip2-devel libffi-devel zlib-devel wget tar gzip -y
+make install-vercel-deps
 
-# install quarto
-wget -q https://github.com/quarto-dev/quarto-cli/releases/download/v1.3.450/quarto-1.3.450-linux-amd64.tar.gz
-tar -xzf quarto-1.3.450-linux-amd64.tar.gz
-export PATH=$PATH:$(pwd)/quarto-1.3.450/bin/
+QUARTO_CMD="./quarto-1.3.450/bin/quarto" make build
 
-
-# setup python env
-python3 -m venv .venv
-source .venv/bin/activate
-python3 -m pip install --upgrade pip
-python3 -m pip install --upgrade uv
-python3 -m uv pip install -r vercel_requirements.txt
-python3 -m uv pip install -e $(ls ../libs/partners | grep -vE "airbyte|ibm|.md" | xargs -I {} echo "../libs/partners/{}")
-
-# autogenerate integrations tables
-python3 scripts/model_feat_table.py
-
-# copy in external files
-mkdir docs/templates
-cp ../templates/docs/INDEX.md docs/templates/index.md
-python3 scripts/copy_templates.py
-
-cp ../cookbook/README.md src/pages/cookbook.mdx
-
-wget -q https://raw.githubusercontent.com/langchain-ai/langserve/main/README.md -O docs/langserve.md
-python3 scripts/resolve_local_links.py docs/langserve.md https://github.com/langchain-ai/langserve/tree/main/
-
-wget -q https://raw.githubusercontent.com/langchain-ai/langgraph/main/README.md -O docs/langgraph.md
-python3 scripts/resolve_local_links.py docs/langgraph.md https://github.com/langchain-ai/langgraph/tree/main/
-
-# render
-quarto render docs/
-python3 scripts/generate_api_reference_links.py --docs_dir docs
+rm -rf docs
+mv build/output/docs ./