Update .gitignore with more common entries

This adds an ignore for the `.vscode` directory used by VS Code projects
and the `.venv` directory used for python virtual environments.
diff --git a/.gitignore b/.gitignore
index 534b538..4433574 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,4 +4,8 @@
 
 # Python
 __pycache__
+.venv
+
+# IDEs
+.vscode