Revert "Add collapsible README sections"

This reverts commit 22e060a.

Author: simonesiega

README.md

@@ -60,9 +60,6 @@
 - [License](#license)
 - [Contributors](#contributors)
 
-<details>
-<summary>Example preview</summary>
-
 ## Example preview
 
 <p align="center">
@@ -75,11 +72,6 @@
 
 The preview shows a representative page from the archive, demonstrating the shared layout for headings, text, diagrams, equations, cross-references, source notes, and code listings.
 
-</details>
-
-<details>
-<summary>Overview</summary>
-
 ## Overview
 
 This repository is the academic archive for the 2026–2029 cohort of the three-year Bachelor's degree programme in Computer Engineering at the University of Padua.
@@ -88,11 +80,6 @@ It collects notes, summaries, diagrams, exercises, references, and other study m
 
 The archive serves both as an active study workspace and as a record of the material covered for each exam.
 
-</details>
-
-<details>
-<summary>Browse the notes</summary>
-
 ## Browse the notes
 
 The archive uses the following fixed degree-year and academic-year mapping:
@@ -107,8 +94,6 @@ The archive uses the following fixed degree-year and academic-year mapping:
 
 The degree-year directories contain the LaTeX sources and supporting files needed to reproduce each PDF. Pull-request builds are uploaded as temporary GitHub Actions artifacts for review and retained for approximately 14 days. Stable end-of-semester editions are published as immutable snapshot releases. Weekly generated changelogs under [`CHANGELOG/`](CHANGELOG/) record committed course-source changes, grouped by date and linked to the corresponding commit.
 
-</details>
-
 ## Exams covered
 
 The archive is updated as new material is written, reviewed, and completed. An exam is considered **covered** only when its intended notes are sufficiently complete, have been reviewed, and have been approved by the repository maintainer. Publishing an immutable semester snapshot explicitly approves every PDF included in that snapshot; the tables below are generated from published GitHub Releases and must not be edited manually.
@@ -134,9 +119,6 @@ Current covered exams:
 | [`notes-latest`](https://github.com/simonesiega/unipd-computer-engineering/releases/tag/notes-latest) | 2026-08-04 | Latest compiled notes | — |
 <!-- RELEASE-CATALOG:END -->
 
-<details>
-<summary>Quick start</summary>
-
 ## Quick start
 
 Clone the repository, then build a course in the pinned TeX Live environment used by CI. Replace `1/course-name` with the course path you want to build.
@@ -151,8 +133,6 @@ For daily work, the equivalent shortcut is `make build COURSE=1/course-name`; ru
 
 The course PDF remains under `.build/<year>/<course>/main.pdf` for local review; generated course PDFs must not be committed. The canonical build requires Docker Compose. Native TeX installations remain useful for previews, but release and CI builds use the pinned container. See [Installation](docs/md/getting-started/installation.md) for prerequisites, [Docker builds](docs/md/getting-started/docker.md) for container setup and troubleshooting, and [Building documents](docs/md/getting-started/building-documents.md) for build options.
 
-</details>
-
 ## Documentation
 
 The [documentation hub](docs/md/README.md) is the main reference for using, building, and extending the archive.
@@ -165,31 +145,18 @@ The [documentation hub](docs/md/README.md) is the main reference for using, buil
 | Repository internals | [Architecture](docs/md/development/architecture.md) · [Build system](docs/md/development/build-system.md) · [Validation, Tests, and CI](docs/md/development/tool-test-and-ci.md) · [AI-assisted development](docs/md/development/ai-assisted-development.md) |
 | Project policies | [Contributing](CONTRIBUTING.md) · [Report a problem](CONTRIBUTING.md#getting-help-and-reporting-problems) · [Security](SECURITY.md) |
 
-<details>
-<summary>AI-assisted development</summary>
-
 ## AI-assisted development
 
 AI-assisted tools may support course material and repository maintenance, but their output is never authoritative and remains subject to human review. Contributors remain responsible for accuracy, originality, citations, licensing, academic integrity, and disclosing uncertainty or skipped verification.
 
 See [AI-assisted development](docs/md/development/ai-assisted-development.md) for the repository's agent guidance, responsibilities, and review requirements.
 
-</details>
-
-<details>
-<summary>Contributing</summary>
-
 ## Contributing
 
 Contributions to the 2026–2029 cohort's study materials, LaTeX system, documentation, and repository tooling are welcome from all students and other contributors. Before opening an issue or pull request, read [`CONTRIBUTING.md`](CONTRIBUTING.md) for contribution paths, quality standards, licensing requirements, validation steps, and academic-integrity rules.
 
 Security vulnerabilities involving scripts, dependencies, automation, or configuration should be reported according to [`SECURITY.md`](SECURITY.md).
 
-</details>
-
-<details>
-<summary>Academic disclaimer</summary>
-
 ## Academic disclaimer
 
 This is an independent and unofficial repository. It is not affiliated with, maintained by, or endorsed by the University of Padua.
@@ -198,8 +165,6 @@ The materials may contain errors, incomplete explanations, missing topics, perso
 
 Always verify important information against official university resources, course instructors, syllabi, textbooks, and teaching materials. The University of Padua name, logo, and related marks are the property of their respective owners. The logo is displayed solely to identify the institution associated with the degree programme; its use does not imply affiliation, authorization, or endorsement.
 
-</details>
-
 ## License
 
 | Material | License |