README - Fix all broken doc references

[deyanzz]

Problem

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

Cryptocurrency

• [ ] CryptoTransferTransaction

Smart Contract

• [ ] ContractRecordsQuery

File

• [ ] FileId
• [ ] FileInfo

---

• [ ] FileCreateTransaction
• [ ] FileAppendTransaction
• [ ] FileUpdateTransaction

• [ ] FileDeleteTransaction

• [ ] FileContentsQuery
• [ ] FileInfoQuery

Consensus Topic

• [ ] TopicId

• [ ] TopicInfo

• [ ] TopicCreateTransaction
• [ ] TopicUpdateTransaction
• [ ] TopicDeleteTransaction

• [ ] TopicMessageSubmitTransaction

• [ ] ConsensusTopicInfoQuery

System

• [ ] SystemDeleteTransaction
• [ ] SystemUndeleteTransaction
• [ ] FreezeTransaction

Network

• [ ] NetworkVersionQuery

Solution

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

Alternatives

N/A