docs: align repository identity and project entrypoint guidance

[ubugeeei]

Finding

Docs and README still point some identity/documentation paths at the upstream FrameScript project while this fork's primary entrypoint is Vue SFC authoring.

Evidence

• README links FrameScript Docs under frame-script.github.io/FrameScript.
• AGENTS.md says users mainly edit project/project.tsx and project/project.vue.
• Docs should clarify when to edit project.vue versus project.tsx.

Acceptance criteria

• Clarify repository identity and upstream/fork relationship.
• Align English and Japanese docs around project.vue/project.tsx entrypoints.
• Keep links accurate.

[ubugeeei]

対応済みです。修正は PR #1 / commit 9cf4498 に反映済みです。