Add LspInstall for lemminx (XML,XSD,SVG)

[vlcinsky]

LspConfig provides instructions for configuring lemmings LSP server for xml, xsd and svg.

LspInstall does not provide an option to install required binary.

lemmings can be installed as Java project or as simple binary. The simple binary is easy to install but does not allow to use lemmings extensions to the LSP server.

Anyway, the binary provided basic functionality is rich enough so the idea is to use the binary method.

[derektata]

I'll work on a pull request 🙂

[vlcinsky]

@derektata wow - that was really quick. Thanks.

[derektata]

No problem man!