markdownlint: add local copy of config

Having the global config (from openbmc-build-scripts) locally makes
it easier for developers to run the tools and get the same results.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I2c41f3f10bf46303ef75c2ea877017631f478643
diff --git a/.markdownlint.yaml b/.markdownlint.yaml
new file mode 100644
index 0000000..15c9e81
--- /dev/null
+++ b/.markdownlint.yaml
@@ -0,0 +1,3 @@
+default: true
+MD024:
+    siblings_only: true
diff --git a/.prettierrc.yaml b/.prettierrc.yaml
new file mode 100644
index 0000000..a69b879
--- /dev/null
+++ b/.prettierrc.yaml
@@ -0,0 +1,7 @@
+tabWidth: 4
+printWidth: 80
+proseWrap: "always"
+overrides:
+    - files: "*.md"
+      options:
+          tabWidth: 2