Add llvm13, libbsd, python-2.7, and libmd

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "modules/flatpak-shared-modules"]
+	path = modules/flatpak-shared-modules
+	url = https://github.com/flathub/shared-modules.git

modules/flatpak-shared-modules

@@ -0,0 +1 @@
+Subproject commit 087c800ebf0e8109888e829cf3de516ba060124d

modules/libbsd/libbsd.yml

@@ -0,0 +1,8 @@
+name: libbsd
+buildsystem: autotools
+modules:
+  - "libmd.yml"
+sources:
+  - type: archive
+    url: https://libbsd.freedesktop.org/releases/libbsd-0.11.5.tar.xz
+    sha256: 1a9c952525635c1bb6770cb22e969b938d8e6a9d7912362b98ee8370599b0efd

modules/libbsd/libmd.yml

@@ -0,0 +1,6 @@
+name: libmd
+buildsystem: autotools
+sources:
+  - type: archive
+    url: https://libbsd.freedesktop.org/releases/libmd-1.0.4.tar.xz
+    sha256: f51c921042e34beddeded4b75557656559cf5b1f2448033b4c1eec11c07e530f

org.darlinghq.darling.yml

@@ -2,13 +2,20 @@ app-id: org.darlinghq.Darling
 runtime: org.freedesktop.Platform
 runtime-version: '21.08'
 sdk: org.freedesktop.Sdk
+sdk-extensions:
+  - org.freedesktop.Sdk.Extension.llvm13
 command: darling shell
 modules:
   - name: darling
     buildsystem: cmake
     builddir: true
+    build-options:
+      append-path: /usr/lib/sdk/llvm13/bin
+      prepend-ld-library-path: /usr/lib/sdk/llvm13/lib
     modules:
       - modules/fuse/fuse.yml
+      - modules/libbsd/libbsd.yml
+      - modules/flatpak-shared-modules/python2.7/python-2.7.json
     sources:
       - type: git
         url: https://github.com/darlinghq/darling.git