Migrate PPL Documentation from RST to Markdown

Signed-off-by: Kyle Hounslow <kylhouns@amazon.com>

Author: kylehounslow

docs/category.json

@@ -4,8 +4,62 @@
     "user/admin/settings.rst"
   ],
   "bash_calcite": [
-    "user/ppl/interfaces/endpoint.rst",
-    "user/ppl/interfaces/protocol.rst"
+    "user/ppl/interfaces/endpoint.md",
+    "user/ppl/interfaces/protocol.md"
+  ],
+  "ppl_cli_calcite": [
+    "user/ppl/cmd/ad.md",
+    "user/ppl/cmd/append.md",
+    "user/ppl/cmd/bin.md",
+    "user/ppl/cmd/dedup.md",
+    "user/ppl/cmd/describe.md",
+    "user/ppl/cmd/eventstats.md",
+    "user/ppl/cmd/eval.md",
+    "user/ppl/cmd/fields.md",
+    "user/ppl/cmd/fillnull.md",
+    "user/ppl/cmd/grok.md",
+    "user/ppl/cmd/head.md",
+    "user/ppl/cmd/join.md",
+    "user/ppl/cmd/lookup.md",
+    "user/ppl/cmd/parse.md",
+    "user/ppl/cmd/patterns.md",
+    "user/ppl/cmd/rare.md",
+    "user/ppl/cmd/regex.md",
+    "user/ppl/cmd/rename.md",
+    "user/ppl/cmd/multisearch.md",
+    "user/ppl/cmd/replace.md",
+    "user/ppl/cmd/rex.md",
+    "user/ppl/cmd/search.md",
+    "user/ppl/cmd/showdatasources.md",
+    "user/ppl/cmd/sort.md",
+    "user/ppl/cmd/spath.md",
+    "user/ppl/cmd/stats.md",
+    "user/ppl/cmd/streamstats.md",
+    "user/ppl/cmd/subquery.md",
+    "user/ppl/cmd/syntax.md",
+    "user/ppl/cmd/chart.md",
+    "user/ppl/cmd/timechart.md",
+    "user/ppl/cmd/search.md",
+    "user/ppl/cmd/top.md",
+    "user/ppl/cmd/trendline.md",
+    "user/ppl/cmd/where.md",
+    "user/ppl/functions/aggregations.md",
+    "user/ppl/functions/collection.md",
+    "user/ppl/functions/condition.md",
+    "user/ppl/functions/conversion.md",
+    "user/ppl/functions/cryptographic.md",
+    "user/ppl/functions/datetime.md",
+    "user/ppl/functions/expressions.md",
+    "user/ppl/functions/ip.md",
+    "user/ppl/functions/json.md",
+    "user/ppl/functions/math.md",
+    "user/ppl/functions/relevance.md",
+    "user/ppl/functions/statistical.md",
+    "user/ppl/functions/string.md",
+    "user/ppl/functions/system.md",
+    "user/ppl/general/comments.md",
+    "user/ppl/general/datatypes.md",
+    "user/ppl/general/identifiers.md"
   ],
   "sql_cli": [
     "user/dql/expressions.rst",
@@ -21,57 +75,7 @@
     "user/dql/complex.rst",
     "user/dql/metadata.rst"
   ],
-  "ppl_cli_calcite": [
-    "user/ppl/cmd/ad.rst",
-    "user/ppl/cmd/append.rst",
-    "user/ppl/cmd/bin.rst",
-    "user/ppl/cmd/dedup.rst",
-    "user/ppl/cmd/describe.rst",
-    "user/ppl/cmd/eventstats.rst",
-    "user/ppl/cmd/eval.rst",
-    "user/ppl/cmd/fields.rst",
-    "user/ppl/cmd/fillnull.rst",
-    "user/ppl/cmd/grok.rst",
-    "user/ppl/cmd/head.rst",
-    "user/ppl/cmd/join.rst",
-    "user/ppl/cmd/lookup.rst",
-    "user/ppl/cmd/parse.rst",
-    "user/ppl/cmd/patterns.rst",
-    "user/ppl/cmd/rare.rst",
-    "user/ppl/cmd/regex.rst",
-    "user/ppl/cmd/rename.rst",
-    "user/ppl/cmd/multisearch.rst",
-    "user/ppl/cmd/replace.rst",
-    "user/ppl/cmd/rex.rst",
-    "user/ppl/cmd/search.rst",
-    "user/ppl/cmd/showdatasources.rst",
-    "user/ppl/cmd/sort.rst",
-    "user/ppl/cmd/spath.rst",
-    "user/ppl/cmd/stats.rst",
-    "user/ppl/cmd/streamstats.rst",
-    "user/ppl/cmd/subquery.rst",
-    "user/ppl/cmd/syntax.rst",
-    "user/ppl/cmd/chart.rst",
-    "user/ppl/cmd/timechart.rst",
-    "user/ppl/cmd/search.rst",
-    "user/ppl/functions/statistical.rst",
-    "user/ppl/cmd/top.rst",
-    "user/ppl/cmd/trendline.rst",
-    "user/ppl/cmd/where.rst",
-    "user/ppl/functions/collection.rst",
-    "user/ppl/functions/condition.rst",
-    "user/ppl/functions/datetime.rst",
-    "user/ppl/functions/expressions.rst",
-    "user/ppl/functions/ip.rst",
-    "user/ppl/functions/json.rst",
-    "user/ppl/functions/math.rst",
-    "user/ppl/functions/relevance.rst",
-    "user/ppl/functions/string.rst",
-    "user/ppl/functions/conversion.rst",
-    "user/ppl/general/datatypes.rst",
-    "user/ppl/general/identifiers.rst"
-  ],
   "bash_settings": [
-    "user/ppl/admin/settings.rst"
+    "user/ppl/admin/settings.md"
   ]
 }