fix(readme): example headers display

[alexcg1]

With GitHub's new table of contents feature, our current examples show up twice each, because we're wrapping both the emoji and the example title in header tags (because they're in different table cells so can't use single tag).

This PR converts the examples into a list. As a side-effect it'll probably look better on mobile too

Fixes #2263

[alexcg1]

I don't know why so many reviewers got added. Is this automatic? (I submitted the PR using gh command line tool)

[codecov]

Codecov Report

Merging #2264 (64b38d9) into master (0946a46) will decrease coverage by 1.29%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2264      +/-   ##
==========================================
- Coverage   90.56%   89.26%   -1.30%     
==========================================
  Files         209      209              
  Lines       11335    11335              
==========================================
- Hits        10265    10118     -147     
- Misses       1070     1217     +147     

Flag	Coverage Δ
daemon	51.20% <ø> (ø)
jina	89.61% <ø> (-1.42%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
jina/jaml/parsers/flow/v1.py	48.14% <0.00%> (-44.45%)	⬇️
jina/clients/asyncio.py	50.00% <0.00%> (-40.63%)	⬇️
jina/jaml/parsers/flow/legacy.py	22.72% <0.00%> (-20.46%)	⬇️
jina/flow/mixin/async_crud.py	44.59% <0.00%> (-14.87%)	⬇️
jina/flow/base.py	78.00% <0.00%> (-14.58%)	⬇️
jina/flow/asyncio.py	75.00% <0.00%> (-12.50%)	⬇️
jina/jaml/helper.py	87.02% <0.00%> (-6.88%)	⬇️
jina/jaml/parsers/__init__.py	93.61% <0.00%> (-6.39%)	⬇️
jina/clients/__init__.py	89.74% <0.00%> (-5.13%)	⬇️
jina/peapods/runtimes/zmq/zed.py	88.43% <0.00%> (-4.77%)	⬇️
... and 9 more

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[github-actions]

Latency summary

Current PR yields:

• 😶 index QPS at 1017, delta to last 3 avg.: +2%
• 😶 query QPS at 15, delta to last 3 avg.: +2%

Breakdown

Version	Index QPS	Query QPS
current	1017	15
1.1.0	994	14
1.0.16	981	14

Backed by latency-tracking. Further commits will update this comment.

[alexcg1]

Can someone merge? Our CI/CD is failing it