docs: update the titles for all files

docs/spiders/architecture.md

@@ -1,4 +1,4 @@
-## Introduction
+# Spiders architecture
 
 !!! success "Prerequisites"
 

docs/spiders/getting-started.md

@@ -1,3 +1,5 @@
+# Getting started
+
 ## Introduction
 
 !!! success "Prerequisites"

docs/spiders/proxy-blocking.md

@@ -203,7 +203,7 @@ class MySpider(Spider):
         yield {"title": response.css("title::text").get("")}
 ```
 
-What happened above is that I left the blocking detection logic unchanged and made the spider mainly use requests until it gets blocked, then it switches to the stealthy browser.
+What happened above is that I left the blocking detection logic unchanged and had the spider mainly use requests until it got blocked, then switch to the stealthy browser.
 
 
 Putting it all together:

docs/spiders/requests-responses.md

@@ -1,4 +1,4 @@
-## Introduction
+# Requests & Responses
 
 !!! success "Prerequisites"
 

docs/spiders/sessions.md

@@ -1,4 +1,4 @@
-## Introduction
+# Spiders sessions
 
 !!! success "Prerequisites"