README - Fix all broken doc references

### Problem

Some of the doc references seems to be broken or not opening the correct URL. See the list below:

### Cryptocurrency

- [ ] [CryptoTransferTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/cryptocurrency/CryptoTransferTransaction.md)

### Smart Contract

- [ ] [ContractRecordsQuery](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/contract/ContractRecordsQuery.md)

### File

- [ ] [FileId](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FileId.md)
- [ ] [FileInfo](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FileInfo.md)

---
- [ ] [FileCreateTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FileCreateTransaction.md)
- [ ] [FileAppendTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FileAppendTransaction.md)
- [ ] [FileUpdateTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FileUpdateTransaction.md)
- [ ] [FileDeleteTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FileDeleteTransaction.md)
---
- [ ] [FileContentsQuery](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FileContentsQuery.md)
- [ ] [FileInfoQuery](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FileInfoQuery.md)

### Consensus Topic

- [ ] [TopicId](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/TopicId.md)
- [ ] [TopicInfo](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/TopicInfo.md)
---
- [ ] [TopicCreateTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/TopicCreateTransaction.md)
- [ ] [TopicUpdateTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/TopicUpdateTransaction.md)
- [ ] [TopicDeleteTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/TopicDeleteTransaction.md)
- [ ] [TopicMessageSubmitTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/TopicMessageSubmitTransaction.md)
---
- [ ] [ConsensusTopicInfoQuery](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/ConsensusTopicInfoQuery.md)

### System

- [ ] [SystemDeleteTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/SystemDeleteTransaction.md)
- [ ] [SystemUndeleteTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/SystemUndeleteTransaction.md)
- [ ] [FreezeTransaction](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/FreezeTransaction.md)

### Network

- [ ] [NetworkVersionQuery](https://github.com/hashgraph/hedera-sdk-reference/blob/main/reference/NetworkVersionQuery.md)

### Solution

To fix all of the links to open the corresponding `.md` file.

### Alternatives

N/A