Update README file

[lukaszstolarczuk]

It'd be nice to extend the content of our README, proposed updated content:

• extend the lib description,
• differences to other, existing libraries/solutions,
• add info about write ahead/redo log + perhaps some link,
• mention pmemlog,
• add an entry point to examples (extend their description? perhaps not in the top-level README),
• add a fancy image/gif showing how pmemstream works,
• value proposition, e.g.:
  • low latency writes,
  • ...but depends on medium capabilities,
  • low write amplification,
  • low SW overhead = little metadata per entry,
  • transparent usage of DSA/HW accelerators,
  • it's universal and easy to use,
  • does not require (extensive?) PMEM knowledge,
• add a section about testing? rather perhaps write a new blog post about it,
• ...

references: https://pmem.io/blog/2022/01/introduction-to-pmemstream/ https://pmem.io/announcements/2022/pmemstream-v0-2-0-release/ manpages

[lukaszstolarczuk]

Most of these updates are covered by our whitepaper (to be published soon, please look for the link in the README file).

[lukaszstolarczuk]

to be closed when #281 is merged

[lukaszstolarczuk]

At the current state of the product it's not required to update the README. The whitepaper (delivered with 0.2.1 release) should answer most of questions about this project.