Update 01.md

fix typo

01.md

@@ -98,7 +98,7 @@ This NIP defines no rules for how `NOTICE` messages should be sent or treated.
 ## Basic Event Kinds
 
   - `0`: `set_metadata`: the `content` is set to a stringified JSON object `{name: <username>, about: <string>, picture: <url, string>}` describing the user who created the event. A relay may delete past `set_metadata` events once it gets a new one for the same pubkey.
-   * Where `<username>` is a string that matches the pattern: `[\w+\-]` (java regular epression).  Or, in other words, a sequence of the following
+   * Where `<username>` is a string that matches the pattern: `[\w+\-]` (java regular expression).  Or, in other words, a sequence of the following
 	   characters: `[a-zA-Z_\-0-9]`.  <br>
 	   Thus `George-Washington-1776` is a valid `<username>`, but `George Washington` is not. Clients may reject metadata that does not comply.
   - `1`: `text_note`: the `content` is set to the text content of a note (anything the user wants to say).