Copyedit 2020 PWA chapter (#1924)

* Copyedit PWA chapter

* Capitalisation

sql/2020/14_PWA/lighthouse_pwa_audits_sw.sql

@@ -0,0 +1,46 @@
+#standardSQL
+# Get summary of all lighthouse scores for a category for PWA pages
+# Note scores, weightings, groups and descriptions may be off in mixed months when new versions of Lighthouse roles out
+
+CREATE TEMPORARY FUNCTION getAudits(report STRING, category STRING)
+RETURNS ARRAY<STRUCT<id STRING, weight INT64, audit_group STRING, title STRING, description STRING, score INT64>> LANGUAGE js AS '''
+var $ = JSON.parse(report);
+var auditrefs = $.categories[category].auditRefs;
+var audits = $.audits;
+$ = null;
+var results = [];
+for (auditref of auditrefs) {
+  results.push({
+    id: auditref.id,
+    weight: auditref.weight,
+    audit_group: auditref.group,
+    description: audits[auditref.id].description,
+    score: audits[auditref.id].score
+  });
+}
+return results;
+''';
+
+SELECT
+  audits.id AS id,
+  COUNTIF(audits.score > 0) AS num_pages,
+  COUNT(0) AS total,
+  COUNTIF(audits.score IS NOT NULL) AS total_applicable,
+  SAFE_DIVIDE(COUNTIF(audits.score > 0), COUNTIF(audits.score IS NOT NULL)) AS pct,
+  APPROX_QUANTILES(audits.weight, 100)[OFFSET(50)] AS median_weight,
+  MAX(audits.audit_group) AS audit_group,
+  MAX(audits.description) AS description
+FROM
+  `httparchive.lighthouse.2020_08_01_mobile` l,
+  `httparchive.almanac.service_workers` sw,
+  UNNEST(getAudits(report, "pwa")) AS audits
+WHERE
+  date = '2020-08-01' AND
+  client = 'mobile' AND
+  page = l.url AND
+  LENGTH(report) < 20000000  # necessary to avoid out of memory issues. Excludes 16 very large results
+GROUP BY
+  audits.id
+ORDER BY
+  median_weight DESC,
+  id

src/config/2020.json

@@ -633,7 +633,7 @@
       "github": "gregorywolf"
     },
     "hemanth": {
-      "name": "hemanth.hm",
+      "name": "Hemanth HM",
       "teams": [
         "authors"
       ],