Add changelog entries for recent changes

Author: pradyunsg

CHANGELOG.md

@@ -2,7 +2,13 @@
 
 ## unreleased
 
-Nothing.
+* Create https://toml.io as the new primary location to read the TOML spec.
+* Clarify meaning of "quotation marks".
+* Clarify meaning of "expected" value ranges.
+* Clarify that EOF is allowed after key/value pair.
+* Clarify that the various styles for writing keys are equivalent.
+* Clarify that line-ending backslashes must be unescaped in multi-line strings.
+* Add examples for invalid float values.
 
 ## 1.0.0-rc.1 / 2020-04-01