feat: add basic views for Alembic Migrations, Dashboard

can see all "known" migration revisions (per alembic config), and
migrate the DB arbitrarily via alembic upgrade/downgrade

docs/api/wuttaweb.views.alembic.rst

@@ -0,0 +1,6 @@
+
+``wuttaweb.views.alembic``
+==========================
+
+.. automodule:: wuttaweb.views.alembic
+   :members:

docs/conf.py

@@ -28,6 +28,7 @@ templates_path = ["_templates"]
 exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 
 intersphinx_mapping = {
+    "alembic": ("https://alembic.sqlalchemy.org/en/latest/", None),
     "colander": ("https://docs.pylonsproject.org/projects/colander/en/latest/", None),
     "deform": ("https://docs.pylonsproject.org/projects/deform/en/latest/", None),
     "fanstatic": ("https://www.fanstatic.org/en/latest/", None),

docs/index.rst

@@ -58,6 +58,7 @@ the narrative docs are pretty scant.  That will eventually change.
    api/wuttaweb.subscribers
    api/wuttaweb.util
    api/wuttaweb.views
+   api/wuttaweb.views.alembic
    api/wuttaweb.views.auth
    api/wuttaweb.views.base
    api/wuttaweb.views.batch