update prezto

.zprezto/modules/prompt/external/agnoster/README.md

@@ -29,6 +29,53 @@ To test if your terminal and font support it, check that all the necessary chara
 
 ![Screenshot](https://gist.githubusercontent.com/agnoster/3712874/raw/screenshot.png)
 
+## Customize your prompt view
+
+By default prompt has these segments: `prompt_status`, `prompt_context`, `prompt_virtualenv`, `prompt_dir`, `prompt_git`, `prompt_end` in that particular order.
+
+If you want to add, change the order or remove some segments of the prompt, you can use array environment variable named `AGNOSTER_PROMPT_SEGMENTS`.
+
+Examples:
+- Show all segments of the prompt with indices:
+```
+echo "${(F)AGNOSTER_PROMPT_SEGMENTS[@]}" | cat -n
+```
+- Add the new segment of the prompt to the beginning:
+```
+AGNOSTER_PROMPT_SEGMENTS=("prompt_git" "${AGNOSTER_PROMPT_SEGMENTS[@]}")
+```
+- Add the new segment of the prompt to the end:
+```
+AGNOSTER_PROMPT_SEGMENTS+="prompt_end"
+```
+- Insert the new segment of the prompt = `PROMPT_SEGMENT_NAME` on the particular position = `PROMPT_SEGMENT_POSITION`:
+```
+PROMPT_SEGMENT_POSITION=5 PROMPT_SEGMENT_NAME="prompt_end";\
+AGNOSTER_PROMPT_SEGMENTS=("${AGNOSTER_PROMPT_SEGMENTS[@]:0:$PROMPT_SEGMENT_POSITION-1}" "$PROMPT_SEGMENT_NAME" "${AGNOSTER_PROMPT_SEGMENTS[@]:$PROMPT_SEGMENT_POSITION-1}");\
+unset PROMPT_SEGMENT_POSITION PROMPT_SEGMENT_NAME
+```
+- Swap segments 4th and 5th:
+```
+SWAP_SEGMENTS=(4 5);\
+TMP_VAR="$AGNOSTER_PROMPT_SEGMENTS[$SWAP_SEGMENTS[1]]"; AGNOSTER_PROMPT_SEGMENTS[$SWAP_SEGMENTS[1]]="$AGNOSTER_PROMPT_SEGMENTS[$SWAP_SEGMENTS[2]]"; AGNOSTER_PROMPT_SEGMENTS[$SWAP_SEGMENTS[2]]="$TMP_VAR"
+unset SWAP_SEGMENTS TMP_VAR
+```
+- Remove the 5th segment:
+```
+AGNOSTER_PROMPT_SEGMENTS[5]=
+```
+
+A small demo of the dummy custom prompt segment, which has been created with help of the built-in `prompt_segment()` function from Agnoster theme:
+```
+# prompt_segment() - Takes two arguments, background and foreground.
+# Both can be omitted, rendering default background/foreground.
+
+customize_agnoster() {
+  prompt_segment 'red' '' ' ⚙ ⚡⚡⚡ ⚙  '
+}
+```
+![Customization demo](https://github.com/apodkutin/agnoster-zsh-theme/raw/customize-prompt/agnoster_customization.gif)
+
 ## Future Work
 
 I don't want to clutter it up too much, but I am toying with the idea of adding RVM (ruby version) and n (node.js version) display.