[FIX] - remote snippets

[nhussein11]

This PR aims to:

• Fix those links to snippets that weren't updated according to the new IA (mainly asset transfer api page)
• Remove those snippets that can be replaced by a remote source tied to a specific version or tag

Note: I double checked before pushing, but please review this PR carefully since I made many changes that are prone to error

[0xLucca]

LGTM! Just review the PolkadotSDK version in variables.yml

[eshaben]

Nice! Just thinking maybe we should be enforcing the use of variables more frequently?

[eshaben]

Should we be using a variable for v0.3.1?

[nhussein11]

@eshaben I got the following error when trying to do that:

http.client.InvalidURL: URL can't contain control characters. '/paritytech/asset-transfer-api/refs/tags/{{ dependencies.asset_transfer_api.version }}/src/types.ts' (found at least ' ')

[eshaben]

Ah, yeah ok. Thanks for trying!

[nhussein11]

Removing High and Pre-Launch labels, this PR is a nice to have

[eshaben]

Suggested change

	For more information on the underlying types and fields of `RuntimeDispatchInfo`, check the [RuntimeDispatchInfo](https://github.com/polkadot-js/api/blob/v15.0.2/packages/types/src/interfaces/payment/types.ts#L21){target=\_blank} source code.
	For more information on the underlying types and fields of `RuntimeDispatchInfo`, check the [`RuntimeDispatchInfo`](https://github.com/polkadot-js/api/blob/v15.0.2/packages/types/src/interfaces/payment/types.ts#L21){target=\_blank} source code.

[eshaben]

Suggested change

	For more information on the underlying types and fields of `RuntimeDispatchInfoV1`, check the [RuntimeDispatchInfoV1](https://github.com/polkadot-js/api/blob/v15.0.2/packages/types/src/interfaces/payment/types.ts#L28){target=\_blank} source code.
	For more information on the underlying types and fields of `RuntimeDispatchInfoV1`, check the [`RuntimeDispatchInfoV1`](https://github.com/polkadot-js/api/blob/v15.0.2/packages/types/src/interfaces/payment/types.ts#L28){target=\_blank} source code.

[eshaben]

You can use variables in link text, so all these links should be updated. For example this one should be:

Suggested change

	This guide will provide detailed information about the key functionalities offered by the [Asset Conversion](https://github.com/paritytech/polkadot-sdk/tree/polkadot-stable2412/substrate/frame/asset-conversion){target=\_blank} pallet on Asset Hub, including:
	This guide will provide detailed information about the key functionalities offered by the [Asset Conversion](https://github.com/paritytech/polkadot-sdk/tree/{{dependencies.polkadot_sdk.stable_version}}/substrate/frame/asset-conversion){target=\_blank} pallet on Asset Hub, including:

[eshaben]

Sorry for the delay in getting back to you on this one! I think some of these links just need to be revisited, not the snippet ones as I saw your comment on those, but just normal links.

Saw some polkadot-js github references, so lets create a variable for that and use the variable in the links pointing to it