Move all example pallets under examples folder. (#10215)

* Put all examples under one folder

Signed-off-by: Jimmy Chu <jimmychu0807@gmail.com>

* Updated Cargo.toml

Signed-off-by: Jimmy Chu <jimmychu0807@gmail.com>

* updated for ci script

Signed-off-by: Jimmy Chu <jimmychu0807@gmail.com>

* update

Signed-off-by: Jimmy Chu <jimmychu0807@gmail.com>

* Added notes that example pallets are not meant to be used in production.

Signed-off-by: Jimmy Chu <jimmychu0807@gmail.com>

* updated

Signed-off-by: Jimmy Chu <jimmychu0807@gmail.com>

substrate/frame/benchmarking/src/lib.rs

@@ -1217,7 +1217,7 @@ macro_rules! impl_benchmark_test {
 
 /// This creates a test suite which runs the module's benchmarks.
 ///
-/// When called in `pallet_example` as
+/// When called in `pallet_example_basic` as
 ///
 /// ```rust,ignore
 /// impl_benchmark_test_suite!(Pallet, crate::tests::new_test_ext(), crate::tests::Test);
@@ -1243,7 +1243,7 @@ macro_rules! impl_benchmark_test {
 /// }
 /// ```
 ///
-/// When called inside the `benchmarks` macro of the `pallet_example` as
+/// When called inside the `benchmarks` macro of the `pallet_example_basic` as
 ///
 /// ```rust,ignore
 /// benchmarks! {