docs: English translation updates (#190)

* docs: Add CLI article (en)

* docs: Update frames article (en)

* docs: Add article about part models (en)

* docs: Update Raspberry Pi article (en)

* docs: Remove unused raspberry3.jpg

* docs: Add COEX Pix article (en)

* docs: Add CopterHack 2019 article (en)

* docs: Update connection article (en)

* docs: Add programming overview (en)

* docs: Add anchor in modes article

* docs: Fix link in auto_setup, add editing ID (en)

* docs: Rearrange summary to match Russian version (en)

* docs/camera_frame: Add link to cli#editing (en)

* docs/wifi: Fix link to next article (en)

* docs: Add "next" links where appropriate (en)

docs/en/modes.md

@@ -35,7 +35,7 @@ In manual mode the pilot controls the drone directly. GPS, computer vision data,
 * **ALTCTL** (ALTITUDE) — control of the altitude rate, pitch, roll and yaw angular velocity. Requires a barometer or another altitude source.
 * **POSCTL** (POSITION) — control of the altitude rate, forward/backward and right/left speed, and yaw angular velocity. It is the easiest flying mode. The barometer, GPS, computer vision, and other sensors are used.
 
-### Auto flight modes
+### Auto flight modes {#auto}
 
 In autonomous flight modes the quadcopter ignores the control signals from the transmitter and uses a program to fly.