app/model/config-schema.ts - revise documentation for config

It was still talking about config.json, which is no longer being used,
hasn't been for some time. Describe how the current config is set via
a function parameter, and attempt to provide a potted example.

(Part of the conclusion I make is the potted example is forced to be a
bit more complicated than I think is ideal. )

src/map-app/app/model/config-schema.ts

@@ -870,26 +870,121 @@ export class Config implements ReadableConfig, WritableConfig {
   // This generates the documentation for this schema, in Markdown
   generateDoc(): string {
     return [`
-# \`config.json\`
+# \`ConfigData\`
 
-This describes the schema of the \`config.json\` file consuming projects should supply,
-and valid attributes thereof. It should be an object definition. Valid attributes are
-described here. Valid attributes which are not defined in \`config.json\` will take a
-default value. Those which are not valid are ignored.
+This describes the schema of the \`config\` parameter which consuming
+projects should supply to MykoMap via the \`webRun(window: Window,
+base_config: ConfigData): void\` entry-point function, and valid attributes
+thereof.
 
-Here is an example of what you might put in this file:
+The config parameter should be a valid \`ConfigData\` class instance. If
+TypeScript is used this will enforce the allowed attributes and their types
+- this is recommended. In Javascript, it is merely an object - and you may 
+get an error if an attribute defined here is given something unexpected.
+However, attributes not listed here will simply be ignored.
+
+The config parameter hard-wires some defaults for the application at the outset.
+However, these can can still be overridden in various ways by URL
+parameters or HTML element attributes in the web page, as described 
+in [README.md](README.md)
+
+The bare minimum config is the default \`ConfigData\` instance, which 
+is essentially an empty object, but that would result in a totally empty map.
+
+For the sake of illustration, here is an example of what you might put
+in this parameter for a map with pins which have a \`size\`,
+\`description\` and \`address\` field, in addition of the hard-wired
+bare minimum fields of \`uri\`, \`name\`, \`lat\` and \`lng\`. The
+\`size\` field can be one of several pre-defined values - a taxonomy,
+also known as a vocabulary.  Because of the \`filterableFields\`
+attribute, there will be a single drop-down on the search panel for this
+narrowing the displayed pins by values of this field.
+
+\`\`\`
+import { ConfigData } from  "mykomap/app/model/config-schema";
+import { mkObjTransformer, DataVal } from "mykomap/obj-transformer";
+import { InitiativeObj } from "mykomap/src/map-app/app/model/initiative";
+
+const config: ConfigData = {
+  htmlTitle: "Outlets",
+  fields: {
+    address: 'value',
+    size: {
+      type: 'vocab',
+      uri: 'sz:',
+    },
+  },
+  filterableFields: ["size"],
+  vocabularies: [
+    {
+      type: 'json',
+      id: 'vocab',
+      label: 'Vocabs 1.0',
+      url: 'example.json',
+    }
+  ],
+  dataSources: [
+    {
+      id: 'data',
+      label: 'Data',
+      type: 'csv',
+      url: 'example.csv',
+      transform: mkObjTransformer<DataVal, InitiativeObj>({
+        uri: T.prefixed(baseUri).from('Identifier'),
+        name: T.text('').from('Name'),
+        lat: T.nullable.number(null).from('Latitude'),
+        lng: T.nullable.number(null).from('Longitude'),
+        description: T.text('').from('Description'),
+        address: T.text('').from('Address'),
+        size: T.prefixed('https://example.com/size/1.1/').from('Size'),
+      }),
+    },
+  ],
+}
+\`\`\`
+
+This config would need to be accompanied with a \`example.json\` file
+defining the vocabs, and a data file \`example.csv\`. Both of these
+can be supplied in map project source code in the \`www/\` directory,
+or an URL to elsewhere can be supplied. The \`transform\` attribute defines 
+the mapping from CSV fields to map pin fields.
+
+The vocabs file might look like this, which defines one vocabulary: size,
+represented in the config by the abbreviated base URI \`sz:\`. The language 
+isn't specified above, which means it defaults to English, hence there is only one
+language section for \`EN\`, with term labels in English. For example:
 
 \`\`\`
- {
-  "htmlTitle": "Solidarity Oxford",
-  "filterableFields": ["countryId", "primaryActivity"],
-  "doesDirectoryHaveColours": true,
-  "disableClusteringAtZoom": 10
+{
+  "prefixes": {
+    "https://example.com/sizes/1.1/": "sz",
+  },
+  "vocabs": {
+    "sz:": {
+      "EN": {
+        "title": ""
+        "terms": {
+          "sz:large": "Large",
+          "sz:medium": "Medium",
+          "sz:small": "Small",
+        },
+      },
+    }
+  }
 }
 \`\`\`
 
-These values are defaults, however, which can be overridden in various ways,
-as described in [README.md](README.md)
+The data file might look like this, which defines just three pins,
+with some extra fields which are ignored in our example. Some
+identifier field is mandatory, however.
+
+\`\`\`
+Identifier,Name,Description,Address,Size,Latitude,Longitude,Geocoded Latitude,Geocoded Longitude
+1,"Apple Co-op",We grow fruit.","1 Apple Way, Appleton",large,0,0,51.6084367,-3.6547778
+2,"Banana Co","We straighten bananas.","1 Banana Boulevard, Skinningdale",medium,0,0,55.9646979,-3.1733052
+3,"The Cabbage Collective","We are artists.","2 Cabbage Close, Caulfield",small,0,0,54.9744687,-1.6108945
+\`\`\`
+
 
 ## Attributes