[Feature]: Add screenshots to README

[lichangda94-sys]

Feature summary

Add screenshots or placeholder screenshot sections to the README to help users and contributors understand the planned LabTools interface and workflow.

Related module

Documentation

Problem or workflow need

New visitors often decide whether to explore an open-source project based on the README. Screenshots help users quickly understand the purpose, interface direction, and workflow of BioMedPilot-LabTools.

Proposed solution

Add a screenshots section to README.md and README_zh.md.

Initial screenshots can include placeholder images or design mockups if the open-source UI is not available yet.

Suggested screenshot sections:

• LabTools home
• Reagent calculator
• Reagent template manager
• Reagent preparation result
• Western Blot loading calculator
• Planned PCR / qPCR tools
• Planned ELISA tools

Formula or calculation logic

Not applicable.

Expected inputs and outputs

Inputs:

• Screenshot images or placeholder image files
• Short captions
• README screenshot section

Outputs:

• Updated README.md
• Updated README_zh.md
• Optional docs/screenshots/ directory

Example use case

A new contributor visits the repository and can immediately understand what the LabTools module is intended to look like, what workflows it supports, and where they might contribute.

References or notes

If real UI screenshots are not available yet, use simple placeholder images or clearly labeled mockups. Do not include private data, patient data, local file paths, or screenshots from private commercial modules.

Scope check

• This request is for research or laboratory workflow assistance, not clinical diagnosis or treatment decisions.
• I have not included patient data, private laboratory records, API keys, credentials, or confidential protocols.