Add Desktop Windows .nsis instructions

[neuronull]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-27193

📔 Objective

Add documentation for the requirement to have .nsis file adjacent to the installer for Windows builds.

⏰ Reminders before review

• Contributor guidelines followed
• All formatters and local linters executed and passed
• Written new unit and / or integration tests where applicable
• Protected functional changes with optionality (feature flags)
• Used internationalization (i18n) for all UI strings
• CI builds passed
• Communicated to DevOps any deployment requirements
• Updated any necessary documentation (Confluence, contributing docs) or informed the documentation
  team

🦮 Reviewer guidelines

• 👍 (:+1:) or similar for great changes
• 📝 (:memo:) or ℹ️ (:information_source:) for notes or general info
• ❓ (:question:) for questions
• 🤔 (:thinking:) or 💭 (:thought_balloon:) for more open inquiry that's not quite a confirmed
  issue and could potentially benefit from discussion
• 🎨 (:art:) for suggestions / improvements
• ❌ (:x:) or ⚠️ (:warning:) for more significant problems or concerns needing attention
• 🌱 (:seedling:) or ♻️ (:recycle:) for future improvements or indications of technical debt
• ⛏ (:pick:) for minor or nitpick changes

[claude]

Claude finished @neuronull's task in 2m 3s —— View job

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Code Review Complete

• Analyzing PR changes
• Review complete

Summary

This PR adds helpful documentation for Windows .nsis build file requirements. The content is accurate and well-illustrated, but there are a few style guide consistency issues to address.

Findings

♻️ Missing sidebar_position in frontmatter

• All other desktop docs include this field for navigation ordering
• Suggest adding sidebar_position: 5 to frontmatter

🎨 Instructions format

• Style guide calls for numbered instructions starting with action verbs
• Current format has introductory paragraph before list

🎨 Unusual "Figure X:" heading pattern

• No other docs in the repo use this style
• Recommend descriptive headings instead: "Error when .nsis file is missing" and "Pairing the .nsis file with the installer"

🎨 Image alt text formatting

• Using backticks in alt text ( ![`nsis` error]) is inconsistent with other docs
• Recommend plain text: ![nsis error]

Positive aspects

• ✅ Correctly marked as Bitwarden-only content
• ✅ Images properly located and referenced
• ✅ Clear, helpful content with good screenshots

Overall: Approve with suggestions for style consistency improvements.

[github-actions]

Checkmarx One – Scan Summary & Details – 1dc97349-ab4c-403c-b9d4-9541c1695bf3

Great job! No new security vulnerabilities introduced in this pull request

[coltonhurst]

Looks pretty good, thanks for adding this @neuronull!

One general question I'm sure you thought about. Why have this on its own page, versus a small section added under the troubleshooting section? I'm not against it having its own page, but I'm wondering if some things could be made more concise to fit it there?

Another option is keeping the new page and adding the problem to the troubleshooting section with a link to the new page as the solution.

[coltonhurst]

Is there any reason the new page is only visible to Bitwarden developers, instead of both Bitwarden and Community developers? (For readers: to find the page without searching, you have to have "Bitwarden Developer" selected in the top right, unless I'm missing another path.)

[coltonhurst]

Non-blocking thought:

It might be nice to clearly state everything required here, including the .exe download as well as what the final directory state should look like? Just an example:

Suggested change

	1. Download the corresponding `.nsis` file from the build artifacts page.
	2. Place the `.nsis` file in the same folder as the installer. This might require de-compressing the
	download.
	1. Download the standard / beta Windows build (the `.exe` from figure 2)
	2. Download the corresponding `.nsis` file (also seen in figure 2)
	3. Place the `.nsis` file in the same directory as the installer (this might require decompressing the download)
	The final directory state before starting the install should look like:
	{ screenshot or code block with files & extensions listed here }