[graphql/docs] Add initial graphql docs content (MystenLabs#15366)

## Description 

Added an initial draft of the GraphQL docs we want to have. 
`Concepts/GraphQL RPC` 
`Getting-Started/GraphQL RPC`

## Test Plan 

How did you test the new or updated feature?

---
If your changes are not user-facing and not a breaking change, you can
skip the following section. Otherwise, please indicate what changed, and
then add to the Release Notes section as highlighted during the release
process.

### Type of Change (Check all that apply)

- [ ] protocol change
- [ ] user-visible impact
- [ ] breaking change for a client SDKs
- [ ] breaking change for FNs (FN binary must upgrade)
- [ ] breaking change for validators or node operators (must upgrade
binaries)
- [ ] breaking change for on-chain data layout
- [ ] necessitate either a data wipe or data migration

### Release notes

---------

Co-authored-by: ronny-mysten <[email protected]>

crates/sui-graphql-rpc/src/commands.rs

@@ -18,6 +18,7 @@ pub enum Command {
         #[clap(short, long)]
         path: Option<PathBuf>,
     },
+    GenerateDocsExamples,
     GenerateSchema {
         /// Path to output GraphQL schema to, in SDL format.
         #[clap(short, long)]

crates/sui-graphql-rpc/src/examples.rs

@@ -97,6 +97,38 @@ pub fn load_examples() -> anyhow::Result<Vec<ExampleQueryGroup>> {
     Ok(groups)
 }
 
+/// This generates a markdown page with all the examples, to be used in the docs site
+pub fn generate_examples_for_docs() -> anyhow::Result<String> {
+    let groups = load_examples()?;
+
+    let mut output = BufWriter::new(Vec::new());
+    let mut md = Markdown::new(&mut output);
+    md.write(
+        r#"---
+title: Examples
+description: Query examples for working with the Sui GraphQL RPC.
+---
+"#,
+    )?;
+    md.write("This page showcases a number of queries to interact with the network. These examples can also be found in the [repository](https://github.com/MystenLabs/sui/tree/main/crates/sui-graphql-rpc/examples). You can use the [interactive online IDE](https://mainnet.sui.io/rpc/graphql) to run these examples.")?;
+    for group in groups.iter() {
+        let group_name = regularize_string(&group.name);
+        md.write(group_name.heading(2))
+            .map_err(|e| anyhow::anyhow!(e))?;
+        for query in group.queries.iter() {
+            let name = regularize_string(&query.name);
+            md.write(name.heading(3)).map_err(|e| anyhow::anyhow!(e))?;
+            let query = query.contents.lines().collect::<Vec<_>>().join("\n");
+            let content = format!("```graphql\n{}\n```", query);
+            md.write(content.as_str()).map_err(|e| anyhow::anyhow!(e))?;
+        }
+    }
+    let bytes = output.into_inner().map_err(|e| anyhow::anyhow!(e))?;
+    Ok(String::from_utf8(bytes)
+        .map_err(|e| anyhow::anyhow!(e))?
+        .replace('\\', ""))
+}
+
 pub fn generate_markdown() -> anyhow::Result<String> {
     let groups = load_examples()?;
 

crates/sui-graphql-rpc/src/main.rs

@@ -31,6 +31,19 @@ async fn main() {
                 );
             }
         }
+        Command::GenerateDocsExamples => {
+            let mut buf: PathBuf = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+            // we are looking to put examples content in
+            // sui/docs/content/references/sui-api/graphql/examples.mdx
+            let filename = "docs/content/references/sui-api/graphql/examples.mdx";
+            buf.pop();
+            buf.pop();
+            buf.push(filename);
+            let content = sui_graphql_rpc::examples::generate_examples_for_docs()
+                .expect("Generating examples markdown file for docs failed");
+            std::fs::write(buf, content).expect("Writing examples markdown failed");
+            println!("Generated the docs example.mdx file and copied it to {filename}.");
+        }
         Command::GenerateSchema { file } => {
             let out = export_schema();
             if let Some(file) = file {
@@ -43,7 +56,6 @@ async fn main() {
         Command::GenerateExamples { file } => {
             let new_content: String = sui_graphql_rpc::examples::generate_markdown()
                 .expect("Generating examples markdown failed");
-
             let mut buf: PathBuf = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
             buf.push("docs");
             buf.push("examples.md");