Add there "exercises" key to config.json

First step in transitioning from "problems" to "exercises".

Part of exercism/xjava#125.

config.json

@@ -44,6 +44,203 @@
     "pascals-triangle",
     "beer-song"
   ],
+  "exercises": [
+    {
+      "slug": "hello-world",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "etl",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "nucleotide-count",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "word-count",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "pangram",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "anagram",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "hamming",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "bob",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "robot-name",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "meetup",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "phone-number",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "grade-school",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "space-age",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "gigasecond",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "triangle",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "acronym",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "scrabble-score",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "roman-numerals",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "binary",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "prime-factors",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "raindrops",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "allergies",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "strain",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "atbash-cipher",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "accumulate",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "crypto-square",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "trinary",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "rna-transcription",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "hexadecimal",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "sieve",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "simple-cipher",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "octal",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "luhn",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "pig-latin",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "simple-linked-list",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "linked-list",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "nth-prime",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "pascals-triangle",
+      "difficulty": 1,
+      "topics": []
+    },
+    {
+      "slug": "beer-song",
+      "difficulty": 1,
+      "topics": []
+    }
+  ],
   "deprecated": [
   ],
   "ignored": [