[Dubbo] Proofread README.md file with multiple fixes

[royadityak94]

Fixed typo, grammatical, punctuations, and semantic coherence to improve readability and content quality.

What is the purpose of the change

To improve the readability, content quality of the README.md file.

Brief changelog

Fixed typo, grammatical, punctuations, and semantic coherence.

Verifying this change

Doesn't impact the main codebase, and is entirely limited to the README.md file.

Follow this checklist to help us incorporate your contribution quickly and easily:

• Make sure there is a GITHUB_issue field for the change (usually before you start working on it). Trivial changes like typos do not require a GITHUB issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
• Format the pull request title like [Dubbo-XXX] Fix UnknownException when host config not exist #XXX. Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Run mvn clean install -DskipTests=false & mvn clean test-compile failsafe:integration-test to make sure unit-test and integration-test pass.
• If this contribution is large, please follow the Software Donation Guide.

[codecov-io]

Codecov Report

Merging #6807 into master will decrease coverage by 0.08%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #6807      +/-   ##
============================================
- Coverage     59.11%   59.02%   -0.09%     
+ Complexity      509      507       -2     
============================================
  Files          1028     1028              
  Lines         41522    41522              
  Branches       6039     6039              
============================================
- Hits          24547    24510      -37     
- Misses        14203    14232      +29     
- Partials       2772     2780       +8     

Impacted Files	Coverage Δ	Complexity Δ
...rg/apache/dubbo/remoting/utils/PayloadDropper.java	15.38% <0.00%> (-30.77%)	0.00% <0.00%> (ø%)
...he/dubbo/common/threadpool/ThreadlessExecutor.java	52.17% <0.00%> (-10.87%)	0.00% <0.00%> (ø%)
.../apache/dubbo/rpc/protocol/AsyncToSyncInvoker.java	62.06% <0.00%> (-10.35%)	0.00% <0.00%> (ø%)
.../registry/multicast/MulticastServiceDiscovery.java	23.07% <0.00%> (-7.70%)	0.00% <0.00%> (ø%)
...e/dubbo/remoting/transport/netty/NettyChannel.java	55.68% <0.00%> (-4.55%)	20.00% <0.00%> (-1.00%)
.../apache/dubbo/remoting/transport/AbstractPeer.java	63.04% <0.00%> (-4.35%)	0.00% <0.00%> (ø%)
...dubbo/remoting/exchange/support/DefaultFuture.java	74.35% <0.00%> (-4.28%)	0.00% <0.00%> (ø%)
...a/org/apache/dubbo/monitor/dubbo/DubboMonitor.java	86.66% <0.00%> (-2.86%)	16.00% <0.00%> (-1.00%)
...ubbo/registry/client/ServiceDiscoveryRegistry.java	27.84% <0.00%> (-2.54%)	0.00% <0.00%> (ø%)
...pache/dubbo/registry/support/AbstractRegistry.java	79.25% <0.00%> (-1.49%)	0.00% <0.00%> (ø%)
... and 3 more

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[royadityak94]

@ralf0131, @htynkn: Can I request you to review my changes and merge them into the master branch.