Add example for command n,g,p and grid, update date now examples (#4622)

docs/commands/date_now.md

@@ -16,3 +16,13 @@ Get the current date and display it in a given format string.
 ```shell
 > date now | date format "%Y-%m-%d %H:%M:%S"
 ```
+
+Get the time duration from 2019-04-30 to now
+```shell
+> (date now) - 2019-05-01
+```
+
+Get the time duration since a more accurate time
+```shell
+> (date now) - 2019-05-01T04:12:05.20+08:00
+```

docs/commands/g.md

@@ -13,3 +13,15 @@ Switch to a given shell.
 ## Parameters
 
  -  `shell_number`: shell number to change to
+
+## Examples
+
+Make two directories and enter new shells for them, use `g` to jump to the specific shell
+```shell
+> mkdir foo bar; enter foo; enter ../bar; g 1
+```
+
+Use `shells` to show all the opened shells and run `g 2` to jump to the third one
+```shell
+> shells; g 2
+```

docs/commands/grid.md

@@ -15,3 +15,30 @@ Renders the output to a textual terminal grid.
  -  `--width {int}`: number of terminal columns wide (not output columns)
  -  `--color`: draw output with color
  -  `--separator {string}`: character to separate grid with
+
+## Examples
+
+Render a simple list to a grid
+```shell
+> [1 2 3 a b c] | grid
+```
+
+The above example is the same as:
+```shell
+> [1 2 3 a b c] | wrap name | grid
+```
+
+Render a record to a grid
+```shell
+> {name: 'foo', b: 1, c: 2} | grid
+```
+
+Render a list of records to a grid
+```shell
+> [{name: 'A', v: 1} {name: 'B', v: 2} {name: 'C', v: 3}] | grid
+```
+
+Render a table with 'name' column in it to a grid
+```shell
+> [[name patch]; [0.1.0 $false] [0.1.1 $true] [0.2.0 $false]] | grid
+```

docs/commands/n.md

@@ -9,3 +9,15 @@ Switch to the next shell.
 ## Signature
 
 ```> n ```
+
+## Examples
+
+Make two directories and enter new shells for them, use `n` to jump to the next shell
+```shell
+> mkdir foo bar; enter foo; enter ../bar; n
+```
+
+Run `n` several times and note the changes of current directory
+```shell
+> n
+```

docs/commands/p.md

@@ -9,3 +9,15 @@ Switch to the previous shell.
 ## Signature
 
 ```> p ```
+
+## Examples
+
+Make two directories and enter new shells for them, use `p` to jump to the previous shell
+```shell
+> mkdir foo bar; enter foo; enter ../bar; p
+```
+
+Run `p` several times and note the changes of current directory
+```shell
+> p
+```

docs/commands/update_cells.md

@@ -20,8 +20,8 @@ Update the table cells.
 Update the zero value cells to empty strings.
 ```shell
 > [
-    [2021-04-16, 2021-06-10, 2021-09-18, 2021-10-15, 2021-11-16, 2021-11-17, 2021-11-18];
-    [        37,          0,          0,          0,         37,          0,          0]
+    ["2021-04-16", "2021-06-10", "2021-09-18", "2021-10-15", "2021-11-16", "2021-11-17", "2021-11-18"];
+    [          37,            0,            0,            0,           37,            0,            0]
 ] | update cells {|value|
       if $value == 0 {
         ""
@@ -34,8 +34,8 @@ Update the zero value cells to empty strings.
 Update the zero value cells to empty strings in 2 last columns.
 ```shell
 > [
-    [2021-04-16, 2021-06-10, 2021-09-18, 2021-10-15, 2021-11-16, 2021-11-17, 2021-11-18];
-    [        37,          0,          0,          0,         37,          0,          0]
+    ["2021-04-16", "2021-06-10", "2021-09-18", "2021-10-15", "2021-11-16", "2021-11-17", "2021-11-18"];
+    [          37,            0,            0,            0,           37,            0,            0]
 ] | update cells -c ["2021-11-18", "2021-11-17"] {|value|
         if $value == 0 {
           ""