add simple analyzer docs

Signed-off-by: Anton Rubin <[email protected]>

_analyzers/simple.md

@@ -0,0 +1,70 @@
+---
+layout: default
+title: Simple analyzer
+nav_order: 50
+---
+
+# Simple analyzer
+
+The `simple` analyzer is a very basic analyzer that breaks text into terms at non-letter characters and lowercases the terms. Unlike the `standard` analyzer, the `simple` analyzer treats everything except alphabetic characters as delimiters, meaning it does not recognize numbers, punctuation, or special characters as part of the tokens.
+
+## Example configuration
+
+You can use the following command to create index `my_simple_index` with `simple` analyzer:
+
+```json
+PUT /my_simple_index
+{
+  "mappings": {
+    "properties": {
+      "my_field": {
+        "type": "text",
+        "analyzer": "simple"
+      }
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+
+## Configuring custom analyzer
+
+You can use the following command to configure index `my_custom_simple_index` with custom analyzer equivalent to `simple` analyzer but with added `html_strip` character filter:
+
+```json
+PUT /my_custom_simple_index
+{
+  "settings": {
+    "analysis": {
+      "char_filter": {
+        "html_strip": {
+          "type": "html_strip"
+        }
+      },
+      "tokenizer": {
+        "my_lowercase_tokenizer": {
+          "type": "lowercase"
+        }
+      },
+      "analyzer": {
+        "my_custom_simple_analyzer": {
+          "type": "custom",
+          "char_filter": ["html_strip"],
+          "tokenizer": "my_lowercase_tokenizer",
+          "filter": ["lowercase"]
+        }
+      }
+    }
+  },
+  "mappings": {
+    "properties": {
+      "my_field": {
+        "type": "text",
+        "analyzer": "my_custom_simple_analyzer"
+      }
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+