Specification 1.0 simplify

[duhengforever]

After a period of public review, many messaging experts gave lots of valuable suggestions, and many of them thought that the specification is not concise, contains some fields that are not related to the messaging field, such as the transactionId field, even though many messaging middleware supports the transaction in different ways.
So in the next, I personally think that we should polish and simplify the specification field-by-field, and welcome everyone to leave a comment in this issue.

[vongosling]

I agree, +1

[duhengforever]

For better collaboration, we can also directly comment in the Google doc: https://docs.google.com/document/d/1FfVk8jJSOgblNDtkKjJBswnusdNi6WZswLmBvWCueyU/edit?usp=sharing