[graphql/rpc] Auto create markdown doc from examples (MystenLabs#14492)

## Description 

As discussed with @stefan-mysten this starts the auto doc workflow
It could be prettier but it gets the ball rolling

## Test Plan 

Manual

---
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

Cargo.toml

@@ -333,6 +333,7 @@ json_to_table = { git = "https://github.com/zhiburt/tabled/", rev = "e449317a1c0
 leb128 = "0.2.5"
 linked-hash-map = "0.5.6"
 lru = "0.10"
+markdown-gen = "1.2.1"
 match_opt = "0.1.2"
 mime = "0.3"
 mockall = "0.11.4"

crates/sui-graphql-rpc/Cargo.toml

@@ -8,6 +8,7 @@ edition = "2021"
 
 
 [dependencies]
+anyhow.workspace = true
 async-graphql = {workspace = true, features = ["dataloader"] }
 async-graphql-axum.workspace = true
 async-trait.workspace = true
@@ -21,6 +22,7 @@ hex.workspace = true
 hyper.workspace = true
 lru.workspace = true
 move-binary-format.workspace = true
+markdown-gen.workspace = true
 mysten-metrics.workspace = true
 move-core-types.workspace = true
 once_cell.workspace = true
@@ -33,6 +35,7 @@ serde.workspace = true
 serde_json.workspace = true
 serde_with.workspace = true
 serde_yaml.workspace = true
+similar.workspace = true
 sui-types.workspace = true
 telemetry-subscribers.workspace = true
 tracing.workspace = true