Fix ide and vscode markdown link references (#1354)

fixes are:
  1. The following `[]()` url links should've been `[][]` reference
     links:
        - `[Purescript IDE](purescript-ide)`
        - `[LSP plugin](purescript-language-server)`
  2. The following typos were corrected:
        - `purescript-ide` in the link `[Purescript IDE]` was changed to
          match the `ide-purescript` reference in the references table
        - `purescript-langugage-server` was corrected to remove the
          extra g to make it `purescript-language-server` to match the
          url, the reference in the `[LSP Plugin]` link, and proper
          english spelling.

Author: JamesKoenig

README.md

@@ -1625,9 +1625,9 @@ packages, you should run the appropriate package-manager for that (e.g. npm).
 
 Spago dropped support for the --watch flag in `spago build` and `spago test`.
 
-VSCode users are recommended to use the [Purescript IDE](purescript-ide) extension for seamless experiences with automatic rebuilds.
+VSCode users are recommended to use the [Purescript IDE][ide-purescript] extension for seamless experiences with automatic rebuilds.
 
-Users of other editors, e.g. vim, emacs, etc., can make use of the underlying [LSP plugin](purescript-language-server).
+Users of other editors, e.g. vim, emacs, etc., can make use of the underlying [LSP plugin][purescript-language-server].
 
 If you want a very simple drop in replacement for `spago test --watch`, you can use a general purpose tool such as [watchexec]:
 
@@ -1664,6 +1664,6 @@ and similarly for the `test` folder, using that for the test sources.
 [purescript-overlay]: https://github.com/thomashoneyman/purescript-overlay
 [sample-package-set]: https://github.com/purescript/registry/blob/main/package-sets/41.2.0.json
 [watchexec]: https://github.com/watchexec/watchexec#quick-start
-[purescript-langugage-server]: https://github.com/nwolverson/purescript-language-server
+[purescript-language-server]: https://github.com/nwolverson/purescript-language-server
 [ide-purescript]: https://marketplace.visualstudio.com/items?itemName=nwolverson.ide-purescript
 [registry-dev-auth]: https://github.com/purescript/registry-dev/blob/master/SPEC.md#52-authentication