This PR adds an overview of the file structure for the VS Code Extension source code.
I've also simplified the name of a folder.
Test plan
❯ yarn test-integrationyarn run v1.22.17warning @sourcegraph/vscode@2.2.4: The engine "vscode" appears to be invalid.$ TS_NODE_PROJECT=tests/tsconfig.json mocha --parallel=$CI --retries=2 ./tests/**/*.test.ts VS Code extensionDownloading VS Code 1.68.0 from https://update.code.visualstudio.com/1.68.0/darwin-arm64/stableDownloading VS Code [==============================] 100%Downloaded VS Code 1.68.0 into /Users/b/Dev/sourcegraph/client/vscode/.vscode-test/vscode-darwin-1.68.0Starting VS Code { verbose: false, vscodeExecutablePath: '/Users/b/Dev/sourcegraph/client/vscode/.vscode-test/vscode-darwin-1.68.0/Vis'... 43 more characters, userDataDirectory: '/var/folders/g1/f24vdsfn2mb1z2_wwyl5vygh0000gn/T/vsce78yWVY', extensionsDirectory: '/var/folders/g1/f24vdsfn2mb1z2_wwyl5vygh0000gn/T/vsceD159jC'}VSCode started in debug mode on http://127.0.0.1:29378 ✓ works (9969ms) 1 passing (33s)✨ Done in 41.00s.
