i18n all the remaining strings.

frontend/src/app/components/api-docs/api-docs.component.html

@@ -1,7 +1,7 @@
 <ng-container *ngIf="{ val: network$ | async } as network">
 <div class="container-xl">
   <div class="text-center">
-    <h2>{{ network.val === '' ? 'Bitcoin' : network.val.charAt(0).toUpperCase() + network.val.slice(1) }} API Service</h2>
+    <h2>{{ network.val === '' ? 'Bitcoin' : network.val.charAt(0).toUpperCase() + network.val.slice(1) }} <ng-container i18n="api-docs.title">API Service</ng-container></h2>
   </div>
 
   <ul ngbNav #nav="ngbNav" [(activeId)]="active" class="nav-tabs">

frontend/src/app/components/api-docs/api-docs.component.ts

@@ -2,6 +2,7 @@ import { Component, OnInit } from '@angular/core';
 import { StateService } from 'src/app/services/state.service';
 import { WebsocketService } from 'src/app/services/websocket.service';
 import { Observable, merge, of } from 'rxjs';
+import { SeoService } from 'src/app/services/seo.service';
 
 @Component({
   selector: 'app-api-docs',
@@ -16,9 +17,11 @@ export class ApiDocsComponent implements OnInit {
   constructor(
     private stateService: StateService,
     private websocketService: WebsocketService,
+    private seoService: SeoService,
   ) { }
 
   ngOnInit(): void {
+    this.seoService.setTitle($localize`:@@e351b40b3869a5c7d19c3d4918cb1ac7aaab95c4:API`);
     this.network$ = merge(of(''), this.stateService.networkChanged$);
     this.websocketService.want(['blocks']);