Add quick-start help command

scimesh/workloads/help.py

@@ -0,0 +1,65 @@
+"""Quick-start help workload."""
+
+from __future__ import annotations
+
+import argparse
+from textwrap import dedent
+
+
+HELP_TEXT = dedent(
+    """\
+    SciMesh quick start
+    ===================
+
+    SciMesh runs molecular similarity workloads locally. Input must be a ChEMBL TSV
+    with chembl_id and canonical_smiles columns.
+
+    1. Activate the project environment and create a directory for outputs:
+
+       source .venv/bin/activate
+       mkdir -p results
+
+    2. Find molecules similar to gefitinib (CHEMBL939):
+
+       scimesh similarity-search chembl_37_chemreps.txt \\
+         --query-id CHEMBL939 \\
+         --top-k 20 \\
+         --max-rows 10000 \\
+         --output results/gefitinib_top20.csv
+
+    3. Search by a SMILES query instead of a ChEMBL ID:
+
+       scimesh similarity-search chembl_37_chemreps.txt \\
+         --query-smiles 'CCO' \\
+         --top-k 20 \\
+         --output results/smiles_search.csv
+
+    4. Build a small exact similarity graph:
+
+       scimesh similarity-graph chembl_37_chemreps.txt \\
+         --max-rows 1000 \\
+         --threshold 0.7 \\
+         --block-size 250 \\
+         --output results/similarity_graph.csv
+
+    Use --max-rows for quick local tests; omit it to process the full dataset.
+    For all options, run:
+
+       scimesh similarity-search --help
+       scimesh similarity-graph --help
+    """
+)
+
+
+class HelpWorkload:
+    """Expose practical examples without adding special logic to the main CLI."""
+
+    name = "help"
+    help = "Show a quick start and runnable examples."
+
+    def configure_parser(self, parser: argparse.ArgumentParser) -> None:
+        parser.description = "Show SciMesh setup and usage examples."
+
+    def run(self, args: argparse.Namespace) -> int:
+        print(HELP_TEXT)
+        return 0