Remove SVG diagram images from docs, keep prose descriptions

All 7 diagram images removed. The Description heading and full prose
description remain in each file so screen reader and sighted users
get the same content without redundant image/text duplication.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: taylorarndt

docs/01-understanding-github-web-structure.md

@@ -194,8 +194,6 @@ Your personal home (`github.com`) shows activity from repositories you follow. Y
 
 ## 5. Visual Map of a Repository Page
 
-![](images/repo-page-layout-01.svg)
-
 ### Description
 
 A repository home page is laid out from top to bottom as follows. The Global Navigation bar (landmark: "Navigation Menu") contains the GitHub logo, Search, Copilot, Pull Requests, Issues, Notifications bell, and your avatar. Below that are the Repository Tabs (landmark: "Repository navigation") showing Code, Issues (12), Pull requests (3), Actions, and more. Next is the Repository Header, which is the H1 heading "owner / repo-name" plus Star (42), Watch, and Fork (8) buttons. The main content area is split into two columns. On the left is the File Area with the branch selector (main), Go to file button, Code button, and the File Table (a landmark) listing files like .github/, docs/, and README.md with dates. On the right is the Sidebar with the About section, description text, topics (accessibility), Releases (3), Contributors (5), and Languages (Markdown 100%). Below both columns is the rendered README (landmark: "Repository files navigation"), and at the bottom is the Footer.

docs/02-navigating-repositories.md

@@ -29,8 +29,6 @@ Use this sequence before moving to graded chapters:
 
 When you navigate to a GitHub repository (e.g., `https://github.com/owner/repo-name`), you land on the **repository home page** (also called the Code tab). This page has several distinct regions:
 
-![](images/repo-page-layout-02.svg)
-
 ### Description
 
 The repository home page is organized from top to bottom as follows. The Navigation bar (GitHub global nav) contains the avatar menu, Notifications, and search. Below that is the Repository header showing "owner / repo-name" as the H1 heading, plus Star, Watch, and Fork buttons. Next are the Repository navigation tabs (a landmark) with Code (active), Issues, Pull requests, Actions, and more. The main content area is split into two columns: on the left is the File tree / code panel with the branch selector, Files table (navigable as a table), and last commit message; on the right is the Sidebar with the About section, topics, and releases. Below both columns is the rendered README.md in a separate landmark region.

docs/03-the-learning-room.md

@@ -23,8 +23,6 @@ Before starting Chapter 4 challenges, students should be able to:
 2. Explain issue -> branch -> PR -> review -> merge.
 3. Identify where bot feedback appears on PRs.
 
-![](images/learning-room-tree.svg)
-
 #### Description
 
 The learning-room is a single shared repository. It has a protected main branch, and each student opens pull requests against it. For example: Student A's PR #12 is open and assigned to Student B for review, Student B's PR #13 is assigned to Student C, Student C's PR #14 is assigned to Student A, and Student A's earlier PR #11 has already been merged. More PRs appear as students contribute.

docs/12-github-pull-requests-extension.md

@@ -254,8 +254,6 @@ gh pr list --search "review-requested:@me"
 
 ### Pull Request Tree Structure
 
-![](images/pr-tree.svg)
-
 #### Description
 
 The GitHub Pull Requests panel has two top-level sections. "My Pull Requests" contains four filters: Assigned to Me, Created by Me, Waiting for my Review, and All Open. The repository section shows Local Pull Request Branches (checked out locally), All Open Pull Requests, and All Closed Pull Requests.

docs/15-issue-templates.md

@@ -241,8 +241,6 @@ Without this context, maintainers ask follow-up questions - which delays the fix
 
 Templates live in a specific folder in your repository:
 
-![](images/template-folder-tree.svg)
-
 ### Description
 
 Templates live inside your-repo/.github/. The ISSUE_TEMPLATE/ subfolder contains: bug_report.md (Markdown template), feature_request.md (Markdown template), accessibility-bug.yml (YAML form template), and config.yml (template chooser configuration). The pull_request_template.md file sits directly in .github/, not inside ISSUE_TEMPLATE/.

docs/appendix-m-vscode-accessibility-reference.md

@@ -175,8 +175,6 @@ The Accessible Diff Viewer presents file diffs as a structured, line-by-line lis
 
 #### Top-level structure
 
-![](images/diff-viewer-tree.svg)
-
 ##### Description
 
 The Accessible Diff Viewer starts with a header showing the file path and change summary. It then shows each hunk (changed section) in order. Each hunk contains: the hunk location (line range), unchanged context lines, the modified, added, or removed lines with their prefix, and more context lines. After all hunks, a footer shows the totals for additions and deletions.

docs/appendix-q-github-actions-workflows.md

@@ -55,8 +55,6 @@ Think of it as a robot assistant that every repository can optionally configure.
 
 Workflow files live in a specific, mandatory location:
 
-![](images/workflow-folder-tree.svg)
-
 ### Description
 
 Workflow files live at your-repository/.github/workflows/. Example files include: ci.yml (runs tests on every push or PR), lint.yml (checks code style), a11y-scan.yml (accessibility scanning), and deploy.yml (deploys the site when code merges to main).