Update syntax for && and || statement operators

[rjmholt]

Issue Description

PS 7 adds the && and || pipeline chain operators. These will need implementing in the TM grammar.

Expected Behavior

Highlight && and || like & or ;, highlight pipelines between them as normal

Code Samples

Get-Command -Name 'mycommand' && & mycommand

[msftrncs]

I thought they were already in the syntax, but I cannot find them at this time.

In #155 and #156, I have them in as 'invalid.reserved'.

[rjmholt]

In #155 and #156, I have them in as 'invalid.reserved'.

That's really useful, thanks!

[msftrncs]

@rjmholt, can you link to a PR in PowerShell/PowerShell where this is being added?

Thanks

[msftrncs]

I knew I had seen them in this repo, here they are:

EditorSyntax/PowerShellSyntax.tmLanguage

Lines 365 to 370 in d10ae29

	<dict>
	<key>match</key>
	<string>\|{2}|&amp;{2}|;</string>
	<key>name</key>
	<string>punctuation.terminator.statement.powershell</string>
	</dict>

[rjmholt]

PowerShell/PowerShell-RFC#192