docs: update images and add 'classic session launcher' description

[ironAiken2]

This PR is about updating user_settings for 24.09

Changes:

• From Backend.AI version 24.09, we offer the NEO session launcher as the default launcher. A setting for using the Classic launcher has been added to user settings.
• update Images

Related PR:

• feat: Neo session launcher as a default backend.ai-webui#2220

PDF[ko] : 사용자 설정 페이지 — Backend.AI Web-UI User Guide 24.03 문서.pdf
PDF[en] : User Settings — Backend.AI Web-UI User Guide 24.03 documentation.pdf

[ironAiken2]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• docs: update images and add 'classic session launcher' description #92 👈 (View in Graphite)
• docs: update images and add description of default session launcher #91
• docs: update images and add links to related page #87
• docs: update images and add 'resource policy setting in user modify modal` description #93
• docs: update images for neo session launcher #94
• docs: update vfolder images and descriptions #89
• docs: add session history feature, folder explorer and folder create modal descriptions #86
• docs: use folder explorer and create a new folder in session launcher #90
• main

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[YEONFEEL96]

Modified translation to make document more readable.
Added a missing Korean translation.

• Windows: Unlike its' English spell, '윈도우' is the official way to write in Korean. In this case, we will just use 'Windows' rather than translating it.
• WebUI: Modifying 'Web-UI' to 'WebUI'.