update global theme, and apis diagram.

Author: tjholm

docs/apis.mdx

@@ -12,10 +12,13 @@ Nitric has built-in support for web apps and HTTP API development. The `api` res
 graph LR;
     classDef default line-height:1.2;
 
-    A[Api]-->B[Service A];
-    A-->C[Service B];
+    A(Admin Api)-->B(Service A);
+    A-->C(Service B);
+    D(Public Api)-->B(Service A)
 ```
 
+> An API can route to many nitric services, and services can handle many APIs.
+
 ## Creating APIs
 
 Nitric allows you define named APIs, each with their own routes, middleware, handlers and security.

src/mdx/remark.mjs

@@ -11,11 +11,13 @@ export const remarkPlugins = [
       output: 'svg',
       mermaid: {
         theme: 'base',
+        // TODO: Relocate theme config
         themeVariables: {
-          primaryColor: '#ff0000',
-          secondaryColor: '#00ff00',
+          primaryColor: '#242037',
+          lineColor: '#cad3f5',
+          secondaryColor: '#42424a',
           tertiaryColor: '#0000ff',
-          textColor: '#000000',
+          primaryTextColor: '#cad3f5',
           fontSize: '14px',
           fontFamily: 'Fira Code, monospace',
         },