libcurl/conn: make "connection control" a new subsection

And start off by moving "connection reuse" and "proxies" in there.

I can think of more pages to write for this section coming up.

Closes #381

SUMMARY.md

@@ -202,7 +202,6 @@
     * [Drive with easy](libcurl/drive/easy.md)
     * [Drive with multi](libcurl/drive/multi.md)
     * [Drive with multi\_socket](libcurl/drive/multi-socket.md)
-  * [Connection reuse](libcurl/connectionreuse.md)
   * [Callbacks](libcurl/callbacks.md)
     * [Write data](libcurl/callbacks/write.md)
     * [Read data](libcurl/callbacks/read.md)
@@ -221,14 +220,16 @@
     * [Sending trailers](libcurl/callbacks/trailers.md)
     * [HSTS](libcurl/callbacks/hsts.md)
     * [Prereq](libcurl/callbacks/prereq.md)
+  * [Connection control](libcurl/conn.md)
+    * [Connection reuse](libcurl/conn/reuse.md)
+    * [Proxies](libcurl/conn/proxies.md)
   * [Transfer control](libcurl/control.md)
     * [Stop](libcurl/control/stop.md)
     * [Stop slow transfers](libcurl/control/stopslow.md)
     * [Rate limit](libcurl/control/ratelimit.md)
     * [Progress meter](libcurl/control/meter.md)
     * [Progress callback](libcurl/control/progress-callback.md)
   * [Cleanup](libcurl/cleanup.md)
-  * [Proxies](libcurl/proxies.md)
   * [Post transfer info](libcurl/getinfo.md)
   * [Share data between handles](libcurl/sharing.md)
   * [URL API](libcurl/url.md)

libcurl-http.md

@@ -16,7 +16,7 @@ section.
 
 ## HTTP proxy
 
-See [using Proxies with libcurl](libcurl/proxies.md)
+See [using Proxies with libcurl](libcurl/conn/proxies.md)
 
 ## Sections
 

libcurl/conn.md

@@ -0,0 +1,9 @@
+# Connection control
+
+When doing a transfer with libcurl there is typically a *connection*
+involved. A connection done using an Internet transport protocol like TCP or
+QUIC. Transfers are done *over* connections and libcurl offers a lot of
+concepts for connections and options to control how it works with them.
+
+  * [Connection reuse](conn/reuse.md)
+  * [Proxies](conn/proxies.md)

libcurl/connectionreuse.md → libcurl/conn/reuse.md

@@ -31,5 +31,5 @@ later transfer. Just reuse the multi handle!
 
 ## Sharing the "connection cache"
 
-Since libcurl 7.57.0, applications can use the [share interface](sharing.md)
+Since libcurl 7.57.0, applications can use the [share interface](../sharing.md)
 to have otherwise independent transfers share the same connection pool.

libcurl/names.md

@@ -5,7 +5,7 @@ translated to an Internet address. That is "name resolving". Using a numerical
 IP address directly in the URL usually avoids the name resolve phase, but in
 many cases it is not easy to manually replace the name with the IP address.
 
-libcurl tries hard to [re-use an existing connection](connectionreuse.md)
+libcurl tries hard to [re-use an existing connection](conn/reuse.md)
 rather than to create a new one. The function that checks for an existing
 connection to use is based purely on the name and is performed before any name
 resolving is attempted. That is one of the reasons the re-use is so much

libcurl/sharing.md

@@ -8,7 +8,7 @@ you want.
 ## Multi handle
 
 All easy handles added to the same multi handle automatically share
-[connection cache](connectionreuse.md) and [dns cache](names.md).
+[connection cache](conn/reuse.md) and [dns cache](names.md).
 
 ## Sharing between easy handles