README: add NIP-73 k tag

README.md

@@ -245,56 +245,56 @@ They exist to document what may be implemented by [Nostr](https://github.com/nos
 
 ## Standardized Tags
 
-| name | value | other parameters | NIP |
-| ----------------- | ------------------------------------ | ------------------------------- | ------------------------------------- |
-| `e` | event id (hex) | relay URL, marker, pubkey (hex) | [01](01.md), [10](10.md) |
-| `p` | pubkey (hex) | relay URL, petname | [01](01.md), [02](02.md) |
-| `a` | coordinates to an event | relay URL | [01](01.md) |
-| `d` | identifier | -- | [01](01.md) |
-| `-` | -- | -- | [70](70.md) |
-| `g` | geohash | -- | [52](52.md) |
-| `h` | group id | -- | [29](29.md) |
-| `i` | external identity | proof, url hint | [39](39.md), [73](73.md) |
-| `k` | kind number (string) | -- | [18](18.md), [25](25.md), [72](72.md) |
-| `l` | label, label namespace | -- | [32](32.md) |
-| `L` | label namespace | -- | [32](32.md) |
-| `m` | MIME type | -- | [94](94.md) |
-| `q` | event id (hex) | relay URL | [18](18.md) |
-| `r` | a reference (URL, etc) | -- | [24](24.md), [25](25.md) |
-| `r` | relay url | marker | [65](65.md) |
-| `t` | hashtag | -- | [24](24.md), [34](34.md) |
-| `alt` | summary | -- | [31](31.md) |
-| `amount` | millisatoshis, stringified | -- | [57](57.md) |
-| `bolt11` | `bolt11` invoice | -- | [57](57.md) |
-| `challenge` | challenge string | -- | [42](42.md) |
-| `client` | name, address | relay URL | [89](89.md) |
-| `clone` | git clone URL | -- | [34](34.md) |
-| `content-warning` | reason | -- | [36](36.md) |
-| `delegation` | pubkey, conditions, delegation token | -- | [26](26.md) |
-| `description` | description | -- | [34](34.md), [57](57.md), [58](58.md) |
-| `emoji` | shortcode, image URL | -- | [30](30.md) |
-| `encrypted` | -- | -- | [90](90.md) |
-| `expiration` | unix timestamp (string) | -- | [40](40.md) |
-| `goal` | event id (hex) | relay URL | [75](75.md) |
-| `image` | image URL | dimensions in pixels | [23](23.md), [52](52.md), [58](58.md) |
-| `imeta` | inline metadata | -- | [92](92.md) |
-| `lnurl` | `bech32` encoded `lnurl` | -- | [57](57.md) |
-| `location` | location string | -- | [52](52.md), [99](99.md) |
-| `name` | name | -- | [34](34.md), [58](58.md), [72](72.md) |
-| `nonce` | random | difficulty | [13](13.md) |
-| `preimage` | hash of `bolt11` invoice | -- | [57](57.md) |
-| `price` | price | currency, frequency | [99](99.md) |
-| `proxy` | external ID | protocol | [48](48.md) |
-| `published_at` | unix timestamp (string) | -- | [23](23.md) |
-| `relay` | relay url | -- | [42](42.md), [17](17.md) |
-| `relays` | relay list | -- | [57](57.md) |
-| `server` | file storage server url | -- | [96](96.md) |
-| `subject` | subject | -- | [14](14.md), [17](17.md), [34](34.md) |
-| `summary` | summary | -- | [23](23.md), [52](52.md) |
-| `thumb` | badge thumbnail | dimensions in pixels | [58](58.md) |
-| `title` | article title | -- | [23](23.md) |
-| `web` | webpage URL | -- | [34](34.md) |
-| `zap` | pubkey (hex), relay URL | weight | [57](57.md) |
+| name | value | other parameters | NIP  |
+| ----------------- | ------------------------------------ | ------------------------------- | -------------------------------------------------- |
+| `e` | event id (hex) | relay URL, marker, pubkey (hex) | [01](01.md), [10](10.md)  |
+| `p` | pubkey (hex) | relay URL, petname | [01](01.md), [02](02.md)  |
+| `a` | coordinates to an event | relay URL | [01](01.md)  |
+| `d` | identifier | -- | [01](01.md)  |
+| `-` | -- | -- | [70](70.md)  |
+| `g` | geohash | -- | [52](52.md)  |
+| `h` | group id | -- | [29](29.md)  |
+| `i` | external identity | proof, url hint | [39](39.md), [73](73.md)  |
+| `k` | kind    | -- | [18](18.md), [25](25.md), [72](72.md), [73](73.md) |
+| `l` | label, label namespace | -- | [32](32.md)  |
+| `L` | label namespace | -- | [32](32.md)  |
+| `m` | MIME type | -- | [94](94.md)  |
+| `q` | event id (hex) | relay URL | [18](18.md)  |
+| `r` | a reference (URL, etc) | -- | [24](24.md), [25](25.md)  |
+| `r` | relay url | marker | [65](65.md)  |
+| `t` | hashtag | -- | [24](24.md), [34](34.md)  |
+| `alt` | summary | -- | [31](31.md)  |
+| `amount` | millisatoshis, stringified | -- | [57](57.md)  |
+| `bolt11` | `bolt11` invoice | -- | [57](57.md)  |
+| `challenge` | challenge string | -- | [42](42.md)  |
+| `client` | name, address | relay URL | [89](89.md)  |
+| `clone` | git clone URL | -- | [34](34.md)  |
+| `content-warning` | reason | -- | [36](36.md)  |
+| `delegation` | pubkey, conditions, delegation token | -- | [26](26.md)  |
+| `description` | description | -- | [34](34.md), [57](57.md), [58](58.md)  |
+| `emoji` | shortcode, image URL | -- | [30](30.md)  |
+| `encrypted` | -- | -- | [90](90.md)  |
+| `expiration` | unix timestamp (string) | -- | [40](40.md)  |
+| `goal` | event id (hex) | relay URL | [75](75.md)  |
+| `image` | image URL | dimensions in pixels | [23](23.md), [52](52.md), [58](58.md)  |
+| `imeta` | inline metadata | -- | [92](92.md)  |
+| `lnurl` | `bech32` encoded `lnurl` | -- | [57](57.md)  |
+| `location` | location string | -- | [52](52.md), [99](99.md)  |
+| `name` | name | -- | [34](34.md), [58](58.md), [72](72.md)  |
+| `nonce` | random | difficulty | [13](13.md)  |
+| `preimage` | hash of `bolt11` invoice | -- | [57](57.md)  |
+| `price` | price | currency, frequency | [99](99.md)  |
+| `proxy` | external ID | protocol | [48](48.md)  |
+| `published_at` | unix timestamp (string) | -- | [23](23.md)  |
+| `relay` | relay url | -- | [42](42.md), [17](17.md)  |
+| `relays` | relay list | -- | [57](57.md)  |
+| `server` | file storage server url | -- | [96](96.md)  |
+| `subject` | subject | -- | [14](14.md), [17](17.md), [34](34.md)  |
+| `summary` | summary | -- | [23](23.md), [52](52.md)  |
+| `thumb` | badge thumbnail | dimensions in pixels | [58](58.md)  |
+| `title` | article title | -- | [23](23.md)  |
+| `web` | webpage URL | -- | [34](34.md)  |
+| `zap` | pubkey (hex), relay URL | weight | [57](57.md)  |
 
 Please update these lists when proposing new NIPs.