[Backport 2.18] add uax_url_email tokenizer docs

_analyzers/tokenizers/uax-url-email.md

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+---
+layout: default
+title: UAX URL email
+parent: Tokenizers
+nav_order: 150
+---
+
+# UAX URL email tokenizer
+
+In addition to regular text, the `uax_url_email` tokenizer is designed to handle URLs, email addresses, and domain names. It is based on the Unicode Text Segmentation algorithm ([UAX #29](https://www.unicode.org/reports/tr29/)), which allows it to correctly tokenize complex text, including URLs and email addresses.
+
+## Example usage
+
+The following example request creates a new index named `my_index` and configures an analyzer with a `uax_url_email` tokenizer:
+
+```json
+PUT /my_index
+{
+  "settings": {
+    "analysis": {
+      "tokenizer": {
+        "uax_url_email_tokenizer": {
+          "type": "uax_url_email"
+        }
+      },
+      "analyzer": {
+        "my_uax_analyzer": {
+          "type": "custom",
+          "tokenizer": "uax_url_email_tokenizer"
+        }
+      }
+    }
+  },
+  "mappings": {
+    "properties": {
+      "content": {
+        "type": "text",
+        "analyzer": "my_uax_analyzer"
+      }
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+
+## Generated tokens
+
+Use the following request to examine the tokens generated using the analyzer:
+
+```json
+POST /my_index/_analyze
+{
+  "analyzer": "my_uax_analyzer",
+  "text": "Contact us at support@example.com or visit https://example.com for details."
+}
+```
+{% include copy-curl.html %}
+
+The response contains the generated tokens:
+
+```json
+{
+  "tokens": [
+    {"token": "Contact","start_offset": 0,"end_offset": 7,"type": "<ALPHANUM>","position": 0},
+    {"token": "us","start_offset": 8,"end_offset": 10,"type": "<ALPHANUM>","position": 1},
+    {"token": "at","start_offset": 11,"end_offset": 13,"type": "<ALPHANUM>","position": 2},
+    {"token": "support@example.com","start_offset": 14,"end_offset": 33,"type": "<EMAIL>","position": 3},
+    {"token": "or","start_offset": 34,"end_offset": 36,"type": "<ALPHANUM>","position": 4},
+    {"token": "visit","start_offset": 37,"end_offset": 42,"type": "<ALPHANUM>","position": 5},
+    {"token": "https://example.com","start_offset": 43,"end_offset": 62,"type": "<URL>","position": 6},
+    {"token": "for","start_offset": 63,"end_offset": 66,"type": "<ALPHANUM>","position": 7},
+    {"token": "details","start_offset": 67,"end_offset": 74,"type": "<ALPHANUM>","position": 8}
+  ]
+}
+```
+
+## Parameters
+
+The `uax_url_email` tokenizer can be configured with the following parameter.
+
+Parameter | Required/Optional | Data type | Description
+:--- | :--- | :--- | :--- 
+`max_token_length` | Optional | Integer | Sets the maximum length of the produced token. If this length is exceeded, the token is split into multiple tokens at the length configured in `max_token_length`. Default is `255`.
+