Add Session Loading style to list of known configs (#1077)

* Add Session Loading style to list of known configs

* Update package.json

Co-authored-by: Michael Peyton Jones <[email protected]>

---------

Co-authored-by: Michael Peyton Jones <[email protected]>

Author: fendor

package.json

@@ -209,6 +209,20 @@
           "default": true,
           "description": "Whether to typecheck the entire project on load. It could drive to bad performance in large projects."
         },
+        "haskell.sessionLoading": {
+          "scope": "resource",
+          "type": "string",
+          "enum": [
+            "singleComponent",
+            "multipleComponents"
+          ],
+          "default": "singleComponent",
+          "description": "Preferred approach for loading package components. Setting this to 'multiple components' (EXPERIMENTAL) allows the build tool (such as `cabal` or `stack`) to [load multiple components at once](https://github.com/haskell/cabal/pull/8726), which is a significant improvement.",
+          "enumDescriptions": [
+            "Always load only a single component at a time. This is the most reliable option if you encountered any issues with the other options.",
+            "Prefer a multiple component session, if the build tool supports it. At the moment, only `cabal` supports multiple components session loading. If the `cabal` version does not support loading multiple components at once, we gracefully fall back to \"singleComponent\" mode."
+          ]
+        },
         "haskell.maxCompletions": {
           "scope": "resource",
           "default": 40,