fix(gateways): add missing bidirectional xref metadata

- add xref fields to dnslink-gateway and web-redirects-file specs
- complete xref relationships in path-gateway and subdomain-gateway

Author: lidel

src/http-gateways/dnslink-gateway.md

@@ -17,6 +17,9 @@ editors:
     affiliation:
       name: Cloudflare
       url: https://cloudflare.com/
+xref:
+  - path-gateway
+  - web-redirects-file
 tags: ['httpGateways', 'webHttpGateways']
 order: 4
 ---

src/http-gateways/path-gateway.md

@@ -37,6 +37,8 @@ editors:
 xref:
   - url
   - trustless-gateway
+  - subdomain-gateway
+  - dnslink-gateway
   - ipip-0402
   - ipip-0412
 tags: ['httpGateways', 'lowLevelHttpGateways']

src/http-gateways/subdomain-gateway.md

@@ -42,6 +42,8 @@ editors:
 xref:
   - url
   - html
+  - path-gateway
+  - web-redirects-file
 tags: ['httpGateways', 'webHttpGateways']
 order: 3
 ---

src/http-gateways/web-redirects-file.md

@@ -16,6 +16,9 @@ editors:
     affiliation:
       name: Shipyard
       url: https://ipshipyard.com
+xref:
+  - subdomain-gateway
+  - dnslink-gateway
 tags: ['httpGateways', 'webHttpGateways']
 order: 5
 ---