[SR Tree] Add infotip with explanation about SR Tree

[nishasy]

Summary:

It was a little unclear which graph the SR Tree was for.

Add a clarifying InfoTip explaning that it's for the
"correct answer" graph.

Issue: none

Test plan:

Storybook

• http://localhost:6006/?path=/story/perseuseditor-widgets-interactive-graph--interactive-graph-with-aria-label

[github-actions]

Size Change: +35 B (0%)

Total Size: 1.47 MB

Filename	Size	Change
packages/perseus-editor/dist/es/index.js	689 kB	+35 B (+0.01%)

ℹ️ View Unchanged

Filename	Size
packages/kas/dist/es/index.js	39 kB
packages/keypad-context/dist/es/index.js	760 B
packages/kmath/dist/es/index.js	86.9 kB
packages/math-input/dist/es/index.js	77.7 kB
packages/math-input/dist/es/strings.js	1.79 kB
packages/perseus-core/dist/es/index.js	48.2 kB
packages/perseus-linter/dist/es/index.js	22.1 kB
packages/perseus-score/dist/es/index.js	115 kB
packages/perseus/dist/es/index.js	367 kB
packages/perseus/dist/es/strings.js	6.57 kB
packages/pure-markdown/dist/es/index.js	3.66 kB
packages/simple-markdown/dist/es/index.js	12.5 kB

_{compressed-size-action}

[github-actions]

npm Snapshot: Published

Good news!! We've packaged up the latest commit from this PR (ad670e2) and published it to npm. You
can install it using the tag PR2256.

Example:

yarn add @khanacademy/perseus@PR2256

If you are working in Khan Academy's webapp, you can run:

./dev/tools/bump_perseus_version.sh -t PR2256