doc/tutorial/basics: correct name of section

Change-Id: I8ba748982cbf5fe66535bec87a63c730fd5efb04
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/3601
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/doc/tutorial/basics/6_references/10_operators.txt b/doc/tutorial/basics/6_expressions/10_operators.txt
similarity index 100%
rename from doc/tutorial/basics/6_references/10_operators.txt
rename to doc/tutorial/basics/6_expressions/10_operators.txt
diff --git a/doc/tutorial/basics/6_references/20_interpolation.txt b/doc/tutorial/basics/6_expressions/20_interpolation.txt
similarity index 100%
rename from doc/tutorial/basics/6_references/20_interpolation.txt
rename to doc/tutorial/basics/6_expressions/20_interpolation.txt
diff --git a/doc/tutorial/basics/6_references/25_interpolfield.txt b/doc/tutorial/basics/6_expressions/25_interpolfield.txt
similarity index 100%
rename from doc/tutorial/basics/6_references/25_interpolfield.txt
rename to doc/tutorial/basics/6_expressions/25_interpolfield.txt
diff --git a/doc/tutorial/basics/6_references/40_listcomp.txt b/doc/tutorial/basics/6_expressions/40_listcomp.txt
similarity index 100%
rename from doc/tutorial/basics/6_references/40_listcomp.txt
rename to doc/tutorial/basics/6_expressions/40_listcomp.txt
diff --git a/doc/tutorial/basics/6_references/50_fieldcomp.txt b/doc/tutorial/basics/6_expressions/50_fieldcomp.txt
similarity index 100%
rename from doc/tutorial/basics/6_references/50_fieldcomp.txt
rename to doc/tutorial/basics/6_expressions/50_fieldcomp.txt
diff --git a/doc/tutorial/basics/6_references/55_conditional.txt b/doc/tutorial/basics/6_expressions/55_conditional.txt
similarity index 100%
rename from doc/tutorial/basics/6_references/55_conditional.txt
rename to doc/tutorial/basics/6_expressions/55_conditional.txt
diff --git a/doc/tutorial/basics/6_references/70_regexp.txt b/doc/tutorial/basics/6_expressions/70_regexp.txt
similarity index 100%
rename from doc/tutorial/basics/6_references/70_regexp.txt
rename to doc/tutorial/basics/6_expressions/70_regexp.txt
diff --git a/doc/tutorial/basics/6_references/80_coalesce.txt b/doc/tutorial/basics/6_expressions/80_coalesce.txt
similarity index 100%
rename from doc/tutorial/basics/6_references/80_coalesce.txt
rename to doc/tutorial/basics/6_expressions/80_coalesce.txt