WIP: ReScript 11 migraton guide

Author: fhammerschmidt

data/sidebar_manual_latest.json

@@ -2,6 +2,7 @@
   "Overview": [
     "introduction",
     "installation",
+    "migrate-to-v11-and-uncurried-mode",
     "editor-plugins",
     "try"
   ],

pages/docs/manual/latest/migrate-to-v11-and-uncurried-mode.mdx

@@ -0,0 +1,73 @@
+---
+title: "Migrate to v11 / Uncurried"
+description: "Instructions on upgrading to ReScript 11 with the new uncurried mode"
+canonical: "/docs/manual/latest/migrate-to-v11-and-uncurried-mode"
+---
+
+# Migrate to ReScript 11
+
+## Minimal Migration
+
+This guide describes the things to do at least to migrate to ReScript 11.
+
+### Disable uncurried mode
+
+If you use currying extensively and don't want to bother with adapting your code (or have dependencies )
+
+```json
+{
+  "uncurried": false
+}
+```
+
+## Recommended Migration
+
+### Uncurried Mode
+
+For uncurried mode to take effect in ReScript 11 there is nothing to configure, it is activated by default.
+
+### Adapt suffix
+
+ReScript 11 now allows having arbitrary suffixes in the generated JavaScript files. However it is still recommended to stick to using `.res.js`, `.res.mjs` or `.res.cjs`. For more information, read the Build System Configuration about [suffixes](/docs/manual/latest/build-configuration#suffix).
+
+### rescript.json
+
+The old configuration filename `bsconfig.json` is finally deprecated. Rename it to `rescript.json`.
+
+### ReScript-Core standard library
+
+There is a new standard library in development that can already be installed called ReScript-Core. It replaces the complete `Js` module as well as some of the more frequently used modules from `Belt` and is the recommended standard library to use with uncurried mode. At a later stage it will be integrated into the compiler while `Belt` will be maintaned as a separate npm package.
+
+Until it's integrated in the compiler, it needs to be installed manually:
+
+```console
+$ npm install @rescript/core
+```
+
+Then add `@rescript/core` to your `rescript.json`'s dependencies:
+
+```diff
+ {
+   "bs-dependencies": [
++    "@rescript/core"
+   ]
+ }
+```
+
+Open it so it's available in the global scope.
+
+```diff
+ {
+   "bsc-flags": [
++    "-open RescriptCore",
+   ]
+ }
+```
+
+For a detailed explanation on migration to ReScript-Core, please refer to its [migration guide](https://github.com/rescript-association/rescript-core#migration). A semi-automated script is available as well.
+
+**Note**: ReScript-Core API docs will be added to this documentation platform at a later stage. For now check out the `.resi` files in the repository or, more conveniently, read the docs for a certain module or function directly in the editor tooling.
+
+### Removed bindings
+
+Many Node bindings have been removed from the compiler. Please use [rescript-nodejs](https://github.com/TheSpyder/rescript-nodejs) instead or write your own local bindings.