Update help text everywhere

Author: riquito

README.md

@@ -96,6 +96,12 @@ Memory consumption:
     the whole input in memory (it also happens when -p or -m are being used)
 
     --bytes allocate the whole input in memory
+
+Colors:
+    Help is displayed using colors. Colors will be suppressed in the
+    following circumstances:
+    - when the TERM environment variable is not set or set to "dumb"
+    - when the NO_COLOR environment variable is set (regardless of value)
 ```
 
 ## Examples

doc/tuc.1

@@ -186,6 +186,14 @@ allocates the whole input in memory (it also happens when -p or -m are
 being used)
 .PP
 --bytes allocate the whole input in memory
+.SH COLORS
+.PP
+Help is displayed using colors.
+Colors will be suppressed in the following circumstances:
+.IP \[bu] 2
+when the TERM environment variable is not set or set to \[lq]dumb\[rq]
+.IP \[bu] 2
+when the NO_COLOR environment variable is set (regardless of value)
 .SH BUGS
 .PP
 See GitHub Issues: <https://github.com/riquito/tuc/issues>

doc/tuc.1.md

@@ -116,6 +116,15 @@ MEMORY CONSUMPTION
 
 \--bytes allocate the whole input in memory
 
+COLORS
+======
+
+Help is displayed using colors. Colors will be suppressed in the
+following circumstances:
+
+- when the TERM environment variable is not set or set to "dumb"
+- when the NO_COLOR environment variable is set (regardless of value)
+
 BUGS
 ====
 

src/help.rs

@@ -70,6 +70,12 @@ Memory consumption:
     the whole input in memory (it also happens when -p or -m are being used)
 
     --bytes allocate the whole input in memory
+
+Colors:
+    Help is displayed using colors. Colors will be suppressed in the
+    following circumstances:
+    - when the TERM environment variable is not set or set to "dumb"
+    - when the NO_COLOR environment variable is set (regardless of value)
 "#
 );