Add Solid documentation and SolidStart implementation (#3837)

Author: davedbase

.changeset/fast-nights-rescue.md

@@ -0,0 +1,5 @@
+---
+'@urql/solid': patch
+---
+
+Use `@solid-primitives/utils` for `access` and `MaybeAccessor` utilities instead of custom implementations. This aligns the package with standard Solid ecosystem conventions.

.changeset/tall-paths-roll.md

@@ -0,0 +1,16 @@
+---
+'@urql/solid-start': minor
+---
+
+Initial release of `@urql/solid-start` - URQL integration built with SolidStart's native primitives.
+
+Get started with:
+
+- **`createQuery`** - GraphQL queries using SolidStart's `query()` and `createAsync()`
+- **`createMutation`** - GraphQL mutations using SolidStart's `action()` and `useAction()`
+- **`createSubscription`** - Real-time GraphQL subscriptions
+- **`Provider`** and **`useClient`** - Context-based client access
+- **Reactive variables** - All parameters accept signals/accessors for automatic re-execution
+- **Full SSR support** - Works seamlessly with SolidStart's server-side rendering
+- **TypeScript support** - Complete type safety with GraphQL types
+- **Uses `@solid-primitives/utils`** - Leverages standard Solid ecosystem utilities

docs/README.md

@@ -17,7 +17,7 @@ apps through ["Normalized Caching"](./graphcache/normalized-caching.md).
 `urql` can be understood as a collection of connected parts and packages.
 When we only need to install a single package for our framework of choice. We're then able to
 declaratively send GraphQL requests to our API. All framework packages — like `urql` (for React),
-`@urql/preact`, `@urql/svelte`, and `@urql/vue` — wrap the [core package,
+`@urql/preact`, `@urql/svelte`, `@urql/solid`/`@urql/solid-start` and `@urql/vue` — wrap the [core package,
 `@urql/core`](./basics/core.md), which we can imagine as the brain
 of `urql` with most of its logic. As we progress with implementing `urql` into our application,
 we're later able to extend it by adding ["addon packages", which we call
@@ -33,6 +33,8 @@ We have **Getting Started** guides for:
 - [**React/Preact**](./basics/react-preact.md) covers how to work with the bindings for React/Preact.
 - [**Vue**](./basics/vue.md) covers how to work with the bindings for Vue 3.
 - [**Svelte**](./basics/svelte.md) covers how to work with the bindings for Svelte.
+- [**Solid**](./basics/solid.md) covers how to work with the bindings for Solid.
+- [**SolidStart**](./basics/solid-start.md) covers how to work with the bindings for SolidStart.
 - [**Core Package**](./basics/core.md) covers the shared "core APIs" and how we can use them directly
   in Node.js or imperatively.