Fix scan_step_size in ImporterDM4

add metadata note for mib

Merge branch 'dev' of https://gitee.com/huyiming2016/FourDExplorer into dev

modify docs, add fig for histogram filter, and add notes of .dm4

Fix metadata in ImporterDM4.

Populate basic metadata in ImporterDM4, enable scale bar

fix the bug that dm4 cannot be read

modify about

fix fdd linear not working; mib file cannot calculate virtual image

modify make_packing_windows script

hide plot ctf

hide action ctf

nomalize ctf image

update PagePlotCTF

hide not completed plot ctf