Updated Developers Guide (markdown)

Developers-Guide.md

@@ -2,6 +2,10 @@
 
 ### Frontend
 
+#### Tools used
+
+- [graphql-codegen](https://github.com/dotansimha/graphql-code-generator) for generating typescript types from graphql queries
+
 
 #### Directory structure
 
@@ -30,6 +34,11 @@ src/
 
 ### Backend
 
+#### Tools used
+
+- [sqlc](https://github.com/kyleconroy/sqlc) for converting SQL query files into Golang code
+- [gqlgen](https://github.com/99designs/gqlgen) for converting graphql schema files into Golang code
+
 #### Architecture
 
 ```
@@ -58,3 +67,16 @@ internal/ # all business logic lives here
 migrations/ # a directory of database schema migrations
 
 ```
+
+#### GraphQL schemas
+
+The schema for the API lives as multiple files in the `internal/graph/schema/` folder.
+
+The are converted into a single file (because gqlgen wants that) by a mage target `backend:genSchema`
+
+All primary models live in `_models.gql`
+
+The root Query and Mutation objects live in `_root.gql`
+
+The rest of the files contain domain specific declarations. For instance the Mutations
+for interacting with tasks is in the `task.gql` file.