* nanodet python demo

* add clip

* fix clip wh

* remove nms package requirement

* faster bbox calculation by background score

* Restyled by clang-format

* Restyled by astyle

* Restyled by clang-format

* Restyled by astyle

Co-authored-by: Qoo <r97922153@gmail.com>
Co-authored-by: Restyled.io <commits@restyled.io>

* doc: add build-mlir2ncnn with commit sha and steps

* add mlir git log detail

* arm neon optimization for conv3x3s1 winograd42

* better condition

* Update test_convolution.cpp

* Update test_convolution.cpp

* more proper conditions

* arm neon optimization for general im2col sgemm pack4

* add sgemm

* wip

* wip

* fix armv7 build

* more conditions blah blah

* code format

* fix convolution

* move packed convolution to seperated header source

* unify weight data bf16

* proper conditions

* conv3x3s2 sgemm pack4 test

* feat: add denormal options

Flush-To-Zero(FTZ) and Denormals-Are-Zero(DAZ) are modes that bypass IEEE754 methods of dealing with denormal floating-point numbers on x86_64 and some x86 CPUs.

* feat: Integrate `flush_denormals` into `Extractor::extract`

* chore: replace global variable with `ThreadLocalStorage`

* add bridge image for adreno image storage upload and download

* enable sbn1, print bugbilz flag

* blacklist old adreno

* let user choose use_image_storage option even when bug_storage_buffer_no_l1

* fix model zoo download files

* fix yolov4.bin download split

* fix python/examples/shufflenetv2

Co-authored-by: YoungSoo Lee <youngsoo.lee@navercorp.com>

* fix iOS minimum version,when used Vukan 1.2
* Update IOS mininum version to 9.0

* release python

* fix twine upload only push tags, fix linux bdist_wheel so path error

* fix long_description_content_type

* remove log print

* set cibuildwheel version 1.6.3

* add pyproject.toml

* set release python only on push tag

* add ci build python 2.7

* remove python2.7; update readme.md