added architecture files

[Isaac-Zhang]

What this PR does:
added architecture files: png & pptx

[codecov-io]

Codecov Report

Merging #379 into develop will increase coverage by 0.08%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop     #379      +/-   ##
===========================================
+ Coverage    67.01%   67.09%   +0.08%     
===========================================
  Files          157      157              
  Lines         8239     8239              
===========================================
+ Hits          5521     5528       +7     
+ Misses        2193     2187       -6     
+ Partials       525      524       -1

Impacted Files	Coverage Δ
config/service_config.go	71.96% <0%> (ø)	⬆️
common/url.go	71.15% <0%> (ø)	⬆️
registry/etcdv3/listener.go	76.74% <0%> (ø)	⬆️
filter/filter_impl/generic_filter.go	67.69% <0%> (ø)	⬆️
config_center/apollo/impl.go	87.01% <0%> (ø)	⬆️
config_center/configurator/override.go	75.4% <0%> (ø)	⬆️
config_center/zookeeper/impl.go	40% <0%> (ø)	⬆️
filter/filter_impl/auth/provider_auth.go	52.94% <0%> (ø)	⬆️
registry/zookeeper/registry.go	55.44% <0%> (ø)	⬆️
config/reference_config.go	79.8% <0%> (ø)	⬆️
... and 9 more

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[zouyx]

1. I think the first space should same to the second space.

2. Should more space like provider block.

3. Spacing to parent should be consistent, Config center should be aligned.

@AlexStocks @hxmhlt @fangyincheng

Should the pptx file move to another project, like https://github.com/dubbogo/resources ?

[Isaac-Zhang]

1. I think the first space should same to the second space.

1. Should more space like provider block.

1. Spacing to parent should be consistent, Config center should be aligned.

@AlexStocks @hxmhlt @fangyincheng

Should the pptx file move to another project, like https://github.com/dubbogo/resources ?

1&2&3 Done.

[Isaac-Zhang]

removed the source file of pptx.

[hxmhlt]

Pls remove doc/ dir.

[zouyx]

LGTM , but this line need more straight and remove doc/ dir.

[AlexStocks]

LGTM