Fixing syntax highlighting issue for flexible HEREDOC and NOWDOC in PHP 7.3

As: https://github.com/atom/language-php/pull/357#discussion_r275149488 and https://github.com/a...

Ending terminator also considered as: https://github.com/atom/language-php/pull/357#issuecomment...

begin -> match

Fix PHP tags being injected into PHP source code

🤖 Configure probot/no-response to allow 28 days when requesting more info on an issue

Add Probot no-response configuration

Recognize interpolation in SQL strings in embedded SQL

Use injections for SQL strings

Use // instead of # for PHP comments

Tokenize `yield from`

Tokenize classes that start at a curly brace

Tokenize nullable-type operator

fix heredoc snippet

remove unnecessary space at the end of line

Handle quirk in how PHP parses identifiers

Detect escaping double quotes only in double quoted strings

Add missing optional space to array() construct

Split PHP grammar into separate HTML and PHP portions

Additional changes for the split grammars

Move firstLineMatch back to php.cson

Fixes #182

Add support for ternary and null coalescing operators

Remove potential zero-width injection pattern

Tokenize namespaces when using the scope resolution operator

Add .theme file extension

Fix issues with TextMate compatibility

Allow heredocs to end without a semicolon on the same line

Heredoc terminators must end with a semicolon and EOL

Fixed: Block try...catch now uses \Exception instead of Exception

Correct __toString capitalisation

Always end PHP on ?>

Bring in suggested changes