Fix more typos (#2728)

features/date-to-gmt-string.yml

@@ -1,5 +1,5 @@
 name: toGMTString()
-description: The `toGMTSTring()` method of `Date` objects is an alias to the `toUTCString()` method.
+description: The `toGMTString()` method of `Date` objects is an alias to the `toUTCString()` method.
 spec: https://tc39.es/ecma262/multipage/additional-ecmascript-features-for-web-browsers.html#sec-date.prototype.togmtstring
 discouraged:
   according_to:

features/escape-unescape.yml

@@ -1,5 +1,5 @@
 name: escape() and unescape()
-description: The `escape()` and `unescape()` built-in Javascript methods encode and unencode strings using percent encoding, where certain characters are replaced by hexidecimal escape sequences.
+description: The `escape()` and `unescape()` built-in Javascript methods encode and unencode strings using percent encoding, where certain characters are replaced by hexadecimal escape sequences.
 spec: https://tc39.es/ecma262/multipage/additional-ecmascript-features-for-web-browsers.html#sec-escape-string
 group: javascript
 discouraged:

features/reporting.yml

@@ -1,5 +1,5 @@
 name: Reporting API
-description: The `Reporting-Endpoints` HTTP header and `ReportingObsever()` API send reports of Content Security Policy (CSP) violations, Permissions-Policy violations, deprecated feature usage, browser interventions, and crashes to a nominated URL or callback function.
+description: The `Reporting-Endpoints` HTTP header and `ReportingObserver()` API send reports of Content Security Policy (CSP) violations, Permissions-Policy violations, deprecated feature usage, browser interventions, and crashes to a nominated URL or callback function.
 spec:
   - https://w3c.github.io/reporting/
   - https://wicg.github.io/intervention-reporting/