outline mvp/lists.md for dwyl/app#271

src/SUMMARY.md

@@ -12,4 +12,6 @@
     - [Generate Auth Schema](auth/06-mix-gen-auth.md)
     - [Notes on Naming](auth/07-notes-on-naming.md)
     - [Modals Are An _Antipattern_](auth/08-modals-antipattern.md)
-    - [Encrypt Personal Data](auth/09-encrypt-data.md)
+    - [Encrypt Personal Data](auth/09-encrypt-data.md)
+- [MVP](mvp/README.md)
+  - [Lists][mvp/15-lists.md] 

src/mvp/15-lists.md

@@ -0,0 +1,47 @@
+# Lists
+
+Our **MVP `App`** already has 
+much of the basic functionality we need/want 
+but it's lacking a way to organize
+`items` into distinct projects/areas.
+Let's fix that by introducing `lists`!
+
+## Quick Recap
+
+Until this point we've _deliberately_ kept the `MVP`
+as lean as possible to avoid complexity.
+The ERD is currently just:
+
+![erd-before-lists](https://user-images.githubusercontent.com/194400/231414683-6fce1fd8-aead-471d-8789-a4a0111f7ce8.png)
+
+Just the handful of tables
+you've already seen in the previous sections.
+
+Our reasons for adding `lists` now are:
+**a)** Separate `lists` for different areas of life/work is on our 
+[product roadmap](https://github.com/dwyl/product-roadmap). <br />
+**b)** We want to use `lists` as the basis for organising and 
+[re-ordering `items`](https://github.com/dwyl/mvp/issues/145). <br />
+**c)** `lists` will unlock other functionalty we have planned
+that will make the `App` more _useful_.
+
+
+## Create `Lists` Schema
+
+Create the `lists` and `list_items` database schemas
+with the following 
+[**`mix phx.gen.schema`**](https://hexdocs.pm/phoenix/Mix.Tasks.Phx.Gen.Schema.html)
+commands:
+
+```sh
+mix phx.gen.schema List lists person_id:integer status:integer text:string person_id:integer
+mix phx.gen.schema ListItems list_items item_id:references:items list_id:references:lists position:integer person_id:integer
+```
+
+
+At the end of this step,
+we have the following database
+[Entity Relationship Diagram](https://en.wikipedia.org/wiki/Entity%E2%80%93relationship_model)
+(ERD):
+
+![mvp-erd-list_items](here)

src/mvp/README.md

@@ -0,0 +1,15 @@
+# Minimum Viable Product (MVP)
+
+_All_ Apps start with an MVP. 
+In our case we created a _separate_ repository:
+[github.com/dwyl/**mvp**](https://github.com/dwyl/mvp)
+so that the most _basic_ version of our `App` 
+could be used as a reference by other people building MVPs.
+
+# TODO: 
+
+Lift the contents of 
+[github.com/dwyl/mvp/BUILDIT.md](https://github.com/dwyl/mvp/blob/7c0a29cfe71582a9aada531af339afdd2734b809/BUILDIT.md?plain=1)
+and split it into separate files here in `book`.
+See: 
+[dwyl/mvp/**issues/350**](https://github.com/dwyl/mvp/issues/350)