assignments: fixed multiple errors

* source/compiler_stages/tc_1/code_to_write.rst,
* source/compiler_stages/tc_1/given_code.rst,
* source/compiler_stages/tc_2/given_code.rst,
* source/compiler_stages/tc_3/given_code.rst,
* source/compiler_stages/tc_4/given_code.rst,
* source/compiler_stages/tc_5/given_code.rst,
* source/compiler_stages/tc_6/samples/canonicalization_samples.rst,
* source/compiler_stages/tc_7/given_code.rst,
* source/compiler_stages/tc_8/given_code.rst,
* source/compiler_stages/tc_9/given_code.rst,
* source/compiler_stages/tc_a/improvements.rst,
* source/compiler_stages/tc_a/samples.rst,
* source/compiler_stages/tc_r/given_code.rst,
* source/instructions/coding_style/documentation_style.rst,
* source/instructions/coding_style/use_of_stl.rst,
* source/instructions/tests/generating_the_test_driver.rst,
* source/intro/history/tiger_2002.rst,
* source/intro/history/tiger_2005.rst,
* source/intro/history/tiger_2006.rst,
* source/intro/history/tiger_2007.rst,
* source/intro/history/tiger_2015.rst,
* source/intro/history/tiger_2018.rst,
* source/intro/what_the_tiger_project_is_not.rst,
* source/intro/why_the_tiger_project.rst,
* source/source_code/given_code.rst,
* source/tools/gnu_build_system/package_name_version.rst,
* source/tools/gnu_build_system/setting_defaults.rst,
* source/tools/valgrind.rst: here.
2 jobs for master in 32 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Test
passed #30205
trigger-tc

00:00:32

passed #30141
trigger-tc

00:00:34