Add prefix omon (#1156)

* add omon regex

* added beginning and end for regex

* lint

* edited description

* Add review

---------

Co-authored-by: Ben Gyori <ben.gyori@gmail.com>

src/bioregistry/data/bioregistry.json

@@ -80430,6 +80430,27 @@
     "pattern": "^\\d{7}$",
     "uri_format": "http://purl.obolibrary.org/obo/OMO_$1"
   },
+  "omon": {
+    "contributor": {
+      "email": "oga.t@northeastern.edu",
+      "github": "tomo-oga",
+      "name": "Tomohiro Oga",
+      "orcid": "0009-0001-6787-3995"
+    },
+    "description": "The new national clinical trials registry of the Netherlands",
+    "example": "53367",
+    "homepage": "https://onderzoekmetmensen.nl/en",
+    "logo": "https://onderzoekmetmensen.nl/themes/custom/trialregister/logo.svg",
+    "name": "Overview of Medical Research in the Netherlands",
+    "pattern": "^\\d{5}$",
+    "reviewer": {
+      "email": "b.gyori@northeastern.edu",
+      "github": "bgyori",
+      "name": "Benjamin M. Gyori",
+      "orcid": "0000-0001-9439-5346"
+    },
+    "uri_format": "https://onderzoekmetmensen.nl/en/trial/$1"
+  },
   "omop": {
     "contributor": {
       "email": "cthoyt@gmail.com",