docs: update sdk version to 20.0.0-rc2

docs/basic-tutorials/upgrading-contracts.mdx

@@ -78,7 +78,7 @@ pub fn upgrade(e: Env, new_wasm_hash: BytesN<32>) {
 
 The `update_current_contract_wasm` host function will also emit a `SYSTEM` contract [event] that contains the old and new wasm reference, allowing downstream users to be notified when a contract they use is updated. The event structure will have `topics = ["executable_update", old_executable: ContractExecutable, old_executable: ContractExecutable]` and `data = []`.
 
-[here]: https://docs.rs/soroban-sdk/0.9.2/soroban_sdk/struct.Env.html#method.update_current_contract_wasm
+[here]: https://docs.rs/soroban-sdk/20.0.0-rc2/soroban_sdk/struct.Env.html#method.update_current_contract_wasm
 [event]: ../fundamentals-and-concepts/events.mdx#event-types
 
 ## Tests

docs/basic-tutorials/wasm-metadata.mdx

@@ -38,5 +38,5 @@ contractmeta!(
 pub trait LiquidityPoolTrait {...
 ```
 
-[contractmeta!]: https://docs.rs/soroban-sdk/0.9.2/soroban_sdk/macro.contractmeta.html
+[contractmeta!]: https://docs.rs/soroban-sdk/20.0.0-rc2/soroban_sdk/macro.contractmeta.html
 [liquidity pool example]: https://github.com/stellar/soroban-examples/blob/v20.0.0-rc2/liquidity_pool/src/lib.rs#L152-L155

docs/getting-started/storing-data.mdx

@@ -80,7 +80,7 @@ members = [
 ]
 
 [workspace.dependencies]
-soroban-sdk = "0.9.2"
+soroban-sdk = "20.0.0-rc2"
 
 [profile.release]
 opt-level = "z"