Format docs front page examples

[anatoly-scherbakov]

Summary

• Add an indent parameter to the example() docs macro so admonition body content can be indented correctly when nested inside content tabs.
• Pass indent=4 for all Quick Examples on the docs front page so input and output code blocks render inside the Example admonition.

Test plan

• mkdocs build --strict passes
• Quick Examples tabs on the front page show code inside the Example admonition
• Document loader pages without indent are unchanged

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
lib/pyld
canon.py	218	4	98%	27, 180, 565–566
context_resolver.py	103	8	92%	78, 137, 151, 197, 203–205, 229
iri_resolver.py	141	3	98%	311–312, 322
jsonld.py	2509	166	93%	276–280, 363, 400, 405, 415, 432–447, 483–484, 526, 534, 554, 562–563, 671–676, 756–757, 772–773, 833–838, 863–864, 879–880, 890–891, 917, 958, 968, 974–978, 989–990, 1033, 1040, 1105, 1128, 1150–1152, 1162–1165, 1180, 1203, 1215–1218, 1314, 1326–1329, 1349, 1378, 1411, 1415, 1452, 1495, 1514–1517, 1530, 1579, 1682–1689, 1716–1718, 1744–1747, 1923, 1961, 2373, 2382–2389, 2481, 2508, 2531, 2540, 3117, 3162, 3181, 3246, 3299, 3302, 3365, 3450, 3484, 3492, 3770, 3775, 3777, 3826, 3963–3967, 4071, 4108, 4171, 4406, 4694, 4826, 4860, 4889–4892, 4918–4919, 5102, 5166, 5193, 5267, 5269, 5287, 5385, 5434, 5666, 5668, 5707, 5709, 5718, 5857, 5985, 6072, 6192–6206, 6268, 6270, 6338, 6551, 6557–6561, 6600, 6603, 6693–6694, 6703
lib/pyld/documentloader
aiohttp.py	71	22	69%	29–39, 68, 74, 86, 98–106, 118–121, 138, 153–156
requests.py	49	5	90%	54, 68, 80–88
TOTAL	3279	208	94%

Tests	Skipped	Failures	Errors	Time
1695	44 💤	0 ❌	0 🔥	2m 53s ⏱️