Add lua-enet and lua-https as core plugins;

.gitmodules

@@ -25,3 +25,9 @@
 [submodule "deps/pico-openxr"]
 	path = deps/pico-openxr
 	url = https://github.com/lovr-org/pico_openxr_sdk
+[submodule "plugins/lua-enet"]
+	path = plugins/lua-enet
+	url = https://github.com/bjornbytes/lua-enet
+[submodule "plugins/lua-https"]
+	path = plugins/lua-https
+	url = https://github.com/love2d/lua-https

plugins/README.md

@@ -0,0 +1,17 @@
+Plugins
+===
+
+Plugins are optional native libraries that are built with LÖVR.  CMake will scan `plugins` for any
+folder with a `CMakeLists.txt` and include it in the build.  Any CMake targets the plugin declares
+will automatically include and link with LÖVR's copy of Lua, and any shared libraries they produce
+will be copied next to the `lovr` executable, allowing them to be used from Lua via `require`.
+
+Prebuilt plugin libraries can also be copied next to the lovr executable.  However, this won't work
+easily for Android builds, since the APK requires re-signing if it is modified.
+
+See the [Plugins documentation](https://lovr.org/docs/Plugins) for more info and a list of known
+plugins.
+
+LÖVR includes some "core plugins" here which are included in builds by default.  They are entirely
+optional -- their folders here can be removed or their libraries can be deleted after building
+without disturbing the LÖVR build.

plugins/lua-enet

@@ -0,0 +1 @@
+Subproject commit daaee4ef0056958c33b204a83a97c770ff0a2cbc

plugins/lua-https

@@ -0,0 +1 @@
+Subproject commit 9611092bd2ff96e32832f763b2625567975a5b35