[Doc] Main figure of modles in MMSegmentation

[MengzhangLI]

We would like to add main figure and abstract of each model in our repo. This issue is used for uploading figures for hyperlink in README.md

[MengzhangLI]

ANN:

APCNet:

BiSeNetV1:

BiSeNetV2:

CCNet:

CGNet:

DANet:

DeepLabV3:

DeepLabV3+:

DMNet:

DNL:

DPT:

EMANet:

EncNet:

FastFCN:

Fast-SCNN:

FCN:

GCNet:

HRNet:

ICNet:

ISANet:

MobileNetV2:

MobileNetV3:

NonLocal:

OCRNet:

PointRend:

PSANet:

PSPNet:

ResNest:

SegFormer:

FPN:

SETR:

SwinTransformer:

UNet:

UPerNet:

ViT:

[MengzhangLI]

ERFNet:

[MengzhangLI]

STDC-Seg

[MengzhangLI]

Twins

[MengzhangLI]

segmenter

[MengzhangLI]

K-Net

[RockeyCoss]

HRFormer

[linfangjian01]

BEiT

[MengzhangLI]

MAE

[MengzhangLI]

MaskFormer

[MengzhangLI]

SegNeXt: